Fact-checked by Grok 2 weeks ago

Native metal

A native metal is a mineral consisting of a single metallic element or a naturally occurring alloy of metals found in its pure form in nature, uncombined with other elements or compounds.^[1] These metals are rare due to their tendency to react with oxygen, sulfur, or other substances in the Earth's crust, but they form under specific geological conditions such as low oxidation states or reducing environments.^[2] The most common native metals include gold (Au), silver (Ag), copper (Cu), and platinum (Pt), with rarer occurrences of iron (Fe) and bismuth (Bi).^[1] Native metals typically exhibit high electrical conductivity, malleability, and ductility, properties stemming from their metallic bonding and cubic crystal structures.^[1] They occur in diverse geological settings and have played a pivotal role in human history as some of the first metals used by ancient civilizations due to their accessibility without refining, enabling early metallurgy and trade.^[2] Gold's durability and rarity made it a symbol of wealth, while copper's conductivity enabled tools and other applications. Platinum-group metals are critical for catalytic converters and electronics, often extracted as byproducts from copper-nickel mining.^[3] Today, these metals remain vital resources in global mining.

Definition and Properties

Definition

A native metal is any of the chemical elements that occurs in nature uncombined with other elements, existing in its metallic elemental form rather than as compounds or minerals.^[4]^[5] These occur as pure metals or sometimes as natural alloys, distinguished from ores which require processing to extract the metal.^[6] Primary examples of native metals include gold (Au), silver (Ag), and copper (Cu), as well as the platinum group metals—platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), iridium (Ir), and osmium (Os). Rarer native metals encompass iron (Fe), nickel (Ni), and bismuth (Bi), which are found in isolated or small deposits.^[4]^[5]^[6] Native metals represent the metallic subset of native elements, excluding non-metals such as diamond (carbon) or sulfur, which lack metallic properties despite occurring uncombined.^[4]^[5] Only about 15 metallic elements occur as native metals due to Earth's oxidizing surface conditions, which promote the formation of stable compounds over free metals for most elements. Highly reactive metals tend to bond with oxygen or other elements, while noble metals like gold and platinum resist such reactions and persist in elemental form.^[5]^[6]^[7]

Physical and Chemical Properties

Native metals, primarily noble elements such as gold, silver, and platinum, exhibit distinctive physical properties that distinguish them from more reactive metals and contribute to their persistence in uncombined form in the Earth's crust. These include high density, metallic luster, exceptional malleability, ductility, and superior electrical conductivity. For instance, gold has a density of 19.3 g/cm³, making it one of the densest elements, while platinum reaches 21.45 g/cm³ and silver 10.5 g/cm³.^[8]^[9]^[10] Their characteristic metallic luster arises from the free electrons in their metallic bonding, which reflect light efficiently unless tarnished.^[11] Gold is particularly noted for its malleability, allowing it to be hammered into sheets as thin as 0.0001 mm without breaking, and its ductility enables drawing into wires over 2 km long from a single gram.^[12] These metals also demonstrate high electrical conductivity, with silver possessing the highest among all elements at approximately 6.3 × 10^7 S/m at room temperature, followed closely by gold and copper.^[13] Chemically, native metals are characterized by their low reactivity, a trait that enables them to resist oxidation, corrosion, and other weathering processes over geological timescales, positioning them at the bottom of the reactivity series. This nobility stems from their high standard reduction potentials relative to the standard hydrogen electrode (SHE), indicating a strong tendency to remain in the reduced, metallic state. Gold, for example, has a standard reduction potential of +1.50 V for the Au³⁺/Au couple, silver +0.80 V for Ag⁺/Ag, and platinum +1.18 V for Pt²⁺/Pt, all markedly positive compared to more reactive metals like iron at -0.44 V for Fe²⁺/Fe.^[14] In contrast, reactive metals such as iron readily form stable oxides and sulfides in oxygenated environments, preventing native occurrences except in rare reducing conditions like meteorites, where iron-nickel alloys (kamacite and taenite) form under anaerobic extraterrestrial processes.^[15]^[1] Native metals occasionally occur as natural alloys, sharing similar stability due to the nobility of their components. Electrum, a common pale yellow alloy of gold and silver, typically contains 20-80% gold by weight, with the remainder silver and trace elements like copper.^[16] Similarly, osmiridium is a dense, silvery alloy of osmium and iridium from the platinum group, often with 10-75% osmium, exhibiting extreme hardness and resistance to corrosion.^[17] These alloys inherit the physical and chemical resilience of their parent metals, further enhancing their survival in natural settings.

Historical Significance

Ancient Use

The earliest documented human use of native metals dates to the Neolithic period in the Fertile Crescent, where native copper was collected and shaped as early as 8000 BC. Archaeological evidence from the site of Çayönü in southeastern Turkey reveals copper beads and small ornaments crafted by cold-hammering native copper nuggets found on the surface, without the need for smelting or advanced processing.^[18]^[19] These finds represent the initial exploitation of metals for personal adornment, marking a pivotal shift in human material culture as communities transitioned from stone to incorporating malleable natural resources. Native gold, similarly valued for its ductility, entered use around the same era in the region, with surface-collected nuggets fashioned into simple jewelry, though direct evidence remains sparser than for copper.^[20] By approximately 5000 BC, native silver began appearing in Anatolia, often in the form of rare surface deposits hammered into beads and small items for trade and decoration. In Mesopotamian societies, silver nuggets and fragments served as early prototypes for currency, weighed against standardized measures like barley to facilitate exchange in growing urban centers.^[21]^[22] This pre-smelting phase relied entirely on gathering visible metal deposits from rivers and outcrops, limiting applications to lightweight ornaments, pins, and trade goods due to the absence of extraction techniques. Sites like Çayönü provide key examples of this opportunistic collection, where metals enhanced social status without requiring specialized knowledge.^[23] Native metals held profound cultural significance in ancient societies, symbolizing power, divinity, and eternity. In ancient Egypt, gold embodied the sun god Ra and the imperishable flesh of deities, as seen in the elaborate gold funerary mask of Tutankhamun (ca. 1323 BC), which adorned the pharaoh's mummy to protect his soul in the afterlife. Such uses underscored gold's role in elite rituals and burial practices, reinforcing hierarchical structures. However, exploitation was confined to naturally malleable metals like gold and copper, as harder native metals such as iron remained unworkable without heat treatment; this constraint defined the Chalcolithic Age (ca. 4500–3500 BC), a transitional era blending stone tools with emerging copper artifacts.^[24]

Development of Metallurgy

The discovery and use of native metals laid the groundwork for the development of metallurgy, transitioning from simple cold-working of pure metal deposits to more complex extractive processes. Around 5000 BC, evidence of early copper smelting emerged at the Belovode site in eastern Serbia, part of the Vinča culture, where native copper sources were processed using furnaces to produce slag and metal artifacts. This innovation marked a pivotal shift from relying solely on naturally occurring native metals to extracting them from ores, enabling greater production volumes and alloying experiments that foreshadowed the Bronze Age by approximately 3000 BC across the Near East and Europe. Key milestones in native metal recognition extended to other elements, highlighting regional technological adaptations. In ancient Egypt, native iron from meteorites was valued for its rarity and celestial origins, as exemplified by the iron dagger found in Tutankhamun's tomb, dated to circa 1323 BC, which metallurgical analysis confirmed was forged from meteoric iron containing high nickel content. Similarly, pre-Columbian cultures in South America, including the Muisca of Colombia around 1000 AD, worked with native platinum group metals, creating alloys and artifacts through sintering techniques that demonstrated advanced understanding of refractory metals long before European contact. These developments underscored how native metals served as catalysts for specialized pyrotechnologies and material sciences in isolated civilizations.^[25] The availability of native metals without initial refining needs fostered early economic networks, exemplified by trade routes across Europe that exchanged gold alongside amber, often termed "amber-gold paths." These routes, active from the Bronze Age onward, connected Baltic amber sources to Mediterranean markets, facilitating the flow of native gold from regions like the Carpathians to central Europe and beyond, which bolstered proto-urban economies by integrating luxury goods into long-distance barter systems. Such trade diminished the immediate barriers to metal use, promoting wealth accumulation in emerging societies.^[26] Societally, native metals enabled the weaponization of tools and the establishment of hierarchies, as seen in Sumerian city-states where gold from native deposits adorned temples like those dedicated to Inanna, symbolizing divine favor and royal authority through elaborate statues and votive offerings around 2500 BC. This prestige material reinforced social stratification, with elites controlling access to fuel temple economies and ceremonial displays. However, as accessible native deposits depleted, communities were compelled to innovate ore smelting and refining techniques, driving broader metallurgical advancements that transformed agrarian societies into complex, metal-dependent civilizations.

Geological Formation

Natural Formation Processes

Native metals form through various geological processes that allow metallic elements to exist in their elemental state rather than as compounds, primarily due to their chemical stability in specific environmental conditions. These processes include reduction in low-oxygen settings, mechanical concentration via weathering and erosion, extraterrestrial delivery, and inherent thermodynamic favorability against oxidation.^[1] One primary mechanism is reduction in reducing environments, such as those created by hydrothermal fluids, where metals are liberated from oxides or sulfides and deposited as native elements. In hydrothermal systems, heated groundwater circulates through rocks, dissolving metals like copper and gold from surrounding formations; as these fluids cool or encounter reducing agents like ferrous ions, the metals precipitate in elemental form. For instance, native copper can form when hydrothermal solutions containing copper sulfates interact with ferrous salts at temperatures around 200°C, reducing Cu²⁺ to Cu⁰. Similarly, low-oxygen conditions in serpentinized ultramafic rocks or mid-ocean ridge hydrothermal vents promote the reduction of metals like nickel, leading to native nickel precipitation.^[20]^[27]^[28] Placer deposits and supergene processes further concentrate native metals through surficial weathering and erosion. In placer formation, dense native metals such as gold are eroded from primary lode deposits, transported by rivers, and accumulated in streambeds or gravel bars due to gravity separation from lighter sediments. This mechanical process enriches gold particles, from fine dust to nuggets, in alluvial environments. For copper, supergene enrichment occurs in the oxidized zone above sulfide deposits, where meteoric waters leach copper from hypogene sulfides, and reducing conditions below the water table reprecipitate it as native copper or enriched sulfides like chalcocite.^[20]^[29] Meteoritic origins contribute native metals, particularly siderophile elements like iron and nickel, which are delivered to Earth via iron meteorites. These meteorites consist primarily of an iron-nickel alloy, with nickel comprising 5-10% by weight in most cases, formed in the cores of differentiated planetesimals. Upon impact, fragments of this native metal alloy weather out and become part of terrestrial deposits.^[30] The thermodynamic basis for native metal persistence lies in the unfavorable energetics of their oxidation under Earth surface conditions. Noble metals like gold remain native because the oxidation reaction $4Au + O_2 \rightarrow 2Au_2O_3 has a positive Gibbs free energy change (ΔG°), making the oxide unstable at ambient temperatures; for example, ΔG° for Au₂O₃ formation is positive above 28 K, rendering gold highly resistant to oxidation. This stability, quantified by the equation ΔG° = -2160 + 95.14T - 10.36T log T (in kcal/mol), ensures that native gold does not readily form compounds in oxidizing environments.^[31]

Associated Geological Settings

Native metals are preserved and concentrated in specific geological environments that facilitate their stability against oxidation, often tied to tectonic regimes such as convergent margins, stable cratons, and intraplate rifts. These settings provide structural traps and chemical conditions that allow native elements like gold, silver, platinum-group metals (PGMs), copper, and iron to occur in elemental form rather than as compounds. Hydrothermal, sedimentary, igneous, and rare reduced contexts represent the primary habitats, with global patterns reflecting plate boundary dynamics and ancient continental stability.^[32] Hydrothermal systems, particularly epithermal gold-silver deposits, host native metals in quartz vein and stockwork formations derived from hot, metal-rich fluids ascending from magmatic sources in volcanic arcs. These occur at shallow depths (<1.5 km) and low temperatures (<300°C), commonly in subduction-related settings where fluids interact with cooler host rocks to precipitate native gold and electrum.^[33]^[34] Representative examples include low-sulfidation epithermal veins in andesitic volcanic terrains, where native silver may also form alongside gold.^[35] In sedimentary basins, placer deposits concentrate native gold through mechanical sorting in ancient fluvial systems, often within stable cratonic interiors far from active tectonics. The Archean Witwatersrand Basin in South Africa exemplifies this, with gold-bearing quartz-pebble conglomerates formed around 2.7 billion years ago in a proto-basin setting, representing the largest known repository of detrital native gold on Earth.^[36] These environments preserve heavy native particles winnowed from eroded greenstone belts during periods of low oxygenation.^[37] Igneous associations feature native metals in mafic-ultramafic intrusions and volcanic flows, linked to mantle-derived magmatism in rift or intraplate settings. PGMs, including native platinum and alloys, occur in layered intrusions like the 2.05 Ga Bushveld Complex in South Africa, concentrated in chromitite reefs within ultramafic layers of the Lower and Critical Zones.^[38] Native copper, meanwhile, is disseminated or forms masses in amygdaloidal basalt flows, as seen in the 1.1 Ga Midcontinent Rift-related Portage Lake Volcanics on Michigan's Keweenaw Peninsula, where it fills vesicles and fractures in subaerial lava sequences.^[39]^[40] Rare reduced settings, characterized by anoxic or highly reducing conditions that inhibit oxidation, host native iron in limited terrestrial locales. On Disko Island, Greenland, native iron xenoliths and masses (up to 22 tons) occur within Paleogene basalt flows, formed through assimilation of carbon-rich sediments that created locally oxygen-poor environments during eruption.^[41] Extraterrestrial native iron, derived from meteoritic sources, is also preserved in anoxic deep-water sediments, such as those in the northwest Atlantic, where reducing pore waters prevent alteration.^[42] These occurrences highlight the role of brief, localized reduction in otherwise oxidizing crustal conditions.

Occurrence of Specific Native Metals

Gold

Native gold, the uncombined elemental form of the metal, primarily occurs as nuggets, flakes, and grains within placer deposits, or as veins and disseminated particles in hydrothermal quartz systems. These forms result from the metal's resistance to weathering and erosion, allowing it to concentrate in alluvial environments or remain locked in primary lode sources. Nuggets, which can weigh from grams to tens of kilograms, often exhibit irregular, rounded shapes due to fluvial transport, while finer flakes and dust accumulate in streambeds and gravels.^[43]^[44] The Witwatersrand Basin in South Africa holds the world's largest reserves of native gold, historically accounting for approximately 23% of all gold ever mined through its paleoplacer conglomerates. This basin has yielded over 50,000 tonnes of gold since the late 19th century, underscoring its unparalleled abundance in ancient detrital deposits. Key alluvial placer deposits include those in Alaska's Klondike region, where the 1896 discovery sparked a major gold rush, producing millions of ounces from river gravels rich in native nuggets and flakes derived from eroded lode sources. In contrast, lode deposits dominate in Australia's Kalgoorlie region, particularly the Golden Mile, where native gold occurs in quartz veins within Archaean greenstone terranes, contributing significantly to the country's output. Native gold is frequently alloyed with silver as electrum, a natural Au-Ag solid solution containing 20-80% silver, which alters its pale yellow hue and is common in both placer and vein settings.^[37]^[45]^[46]^[47]^[48] Geologically, native gold is closely associated with quartz veins hosted in greenstone belts, where hydrothermal fluids deposit the metal along shear zones and fractures in volcanic and sedimentary rocks. These belts, formed during Archaean to Proterozoic orogenies, facilitate the focusing of mineralizing fluids that precipitate gold from aqueous solutions. Annual global gold production reached approximately 3,661 tonnes in 2024 (as of early 2025 estimates), with much of the historical output tracing back to native placer and vein sources before the exploitation of refractory ores. Native gold's high purity, often exceeding 99.9% fineness, allows for direct use without refining in many ancient and early mining contexts, though trace elements like silver (typically 1-15% by weight) vary by deposit, influencing alloy composition and color.^[49]^[50]^[51]^[43]^[52]^[53]

Silver

Native silver occurs primarily in hydrothermal vein deposits, where it forms through the precipitation of metallic silver from mineralizing fluids. It commonly appears as dendritic wires, arborescent growths, or thin coatings on host rocks, with rarer well-formed crystals exhibiting cubic, octahedral, or dodecahedral habits. These forms develop in open spaces, fractures, or vugs within the veins, often resulting in intricate, branching structures due to rapid crystallization under low-temperature conditions. Unlike placer deposits, native silver is seldom concentrated in such settings because of its higher reactivity, making it rarer as a native element compared to gold, with significant accumulations limited to specific epithermal environments.^[54]^[55] Major deposits of native silver are found in Mexico, particularly at Fresnillo in Zacatecas, one of the world's largest silver-producing districts, where it contributes to the region's substantial output alongside other silver minerals. In Peru, the Cerro de Pasco district hosts prominent hydrothermal veins rich in native silver, formed through epithermal processes associated with Tertiary volcanic activity. Secondary supergene enrichment plays a key role in some occurrences, where oxidation of primary silver sulfides like argentite (Ag₂S) releases silver ions that redeposit as native metal in enriched zones near the surface, enhancing grades in weathered profiles. These supergene processes are particularly evident in polymetallic districts, leading to higher concentrations of native silver in the oxidized caps above sulfide ores.^[56] Geologically, native silver is often paragenetic with gold, forming electrum alloys (Au-Ag solid solutions) or occurring alongside sulfides such as acanthite, galena, and tetrahedrite in low-sulfidation epithermal systems. Its purity typically reaches 99.9%, though alloying with gold reduces fineness in electrum to 50-80% silver, depending on the deposit's geochemical conditions. Notable examples include the Kongsberg mining district in Norway, renowned for producing exceptional native silver specimens, including large crystalline masses exceeding 10 kg, with the site's historical output highlighting its status as a premier locality for high-quality native silver. Globally, silver production totals approximately 26,000 metric tons annually, with native silver sourced from a minor but significant portion of these deposits, primarily through selective mining of high-grade veins.^[54]^[57]^[58]

Platinum Group Metals

Native platinum group metals (PGMs), which include platinum, palladium, rhodium, ruthenium, iridium, and osmium, occur primarily in the form of nuggets, grains, and alloys rather than pure elemental states.^[59] These alloys commonly feature platinum-iron compositions, such as isoferroplatinum (Pt₃Fe), where platinum dominates but is intergrown with iron and occasionally copper or other PGMs.^[60] Other prevalent forms include Os-Ir-Ru alloys, which appear as dense, resistant grains in ultramafic settings, and rarer iridium-osmium alloys found in association with chromite.^[61] Native PGMs are exceedingly rare in pure form, with most specimens classified as alloys due to their natural intermixing during crystallization.^[62] The global abundance of native PGMs is low, with annual mine production totaling approximately 424 tonnes in 2024.^[63] South Africa's Bushveld Complex serves as the primary source, accounting for over 70% of world PGM output, primarily through layered igneous intrusions where magmatic processes concentrate these elements.^[64] Native platinum nuggets from such deposits typically exhibit high purity, ranging from 95% to 99% platinum, with impurities mainly from iron and minor PGMs.^[65] Key deposits of native PGMs include the historical placers of the Ural Mountains in Russia, where early mining in the 19th century yielded significant platinum grains from river sediments derived from ultramafic sources.^[59] In the United States, the Stillwater Complex in Montana hosts one of the highest-grade PGM reefs, with native alloys occurring in layered mafic intrusions.^[59] Colombia's Chocó region features notable concentrations in beach sands and alluvial placers, where detrital PGM grains, including platinum nuggets, accumulate due to riverine transport from Andean ophiolites.^[66] Geologically, native PGMs form through magmatic segregation in layered intrusions, where dense alloy droplets settle and crystallize within mafic-ultramafic magmas, often stratiform in distribution.^[67] In ophiolite complexes, iridium-osmium alloys crystallize as early phases in ultramafic cumulates, associating with chromite pods in mantle-derived sequences.^[68] Their exceptional resistance to chemical weathering allows native PGMs to persist and concentrate in placers, forming economic detrital deposits far from primary sources.^[69]

Copper

Native copper, occurring as sheets, dendrites, and nuggets, is one of the most abundant native metals due to its widespread occurrence in the Earth's crust compared to rarer elements like gold and platinum.^[27] Its deposits often form through hydrothermal processes in volcanic settings, making it more accessible than the deep intrusive sources typical of platinum group metals.^[70] Significant historical deposits include those in the Keweenaw Peninsula of Michigan, where the district's early mining from 1845 to 1887 marked the peak period, contributing significantly to the total historical output of approximately 4.5 million metric tons of native copper. The Lake Superior region, encompassing this area, features extensive stratiform deposits hosted in the tops of rift-related basaltic lava flows.^[70] In Cyprus, ancient mining of native copper deposits gave rise to the Latin term cuprum, reflecting the island's role as a key Bronze Age supplier.^[71] Similarly, the Timna Valley in Israel yielded native copper from around 5000 BCE, marking one of the earliest known exploitation sites in the Near East.^[72] Geologically, native copper forms through secondary enrichment processes in porphyry copper systems, where supergene weathering oxidizes primary sulfides to precipitate metallic copper near the surface.^[73] It also occurs natively within amygdaloidal basalts, as seen in Michigan's Portage Lake Volcanics, where hydrothermal fluids from late-stage metamorphism fill vesicles and fractures to deposit pure metal.^[74] A unique aspect of native copper is its high purity, often exceeding 99.9%, which allowed early cultures to shape it through cold-working without smelting.^[75] This property underpinned the Old Copper Complex culture in the Great Lakes region from approximately 6000 to 3000 BCE, where Indigenous peoples mined and hammered copper into tools and ornaments, representing one of North America's earliest metallurgical traditions.^[76]

Iron, Nickel, and Cobalt

Native iron, nickel, and cobalt occur infrequently in nature due to the high reactivity of these siderophile elements, which typically bind with oxygen or sulfur under oxidizing conditions prevalent in Earth's crust. Terrestrial occurrences are confined to highly reduced environments, such as serpentinized ultramafic rocks or carbon-bearing volcanic settings, while meteoritic sources provide the majority of known native iron. These metals often form as alloys rather than pure elements, reflecting the geochemical conditions that prevent oxidation.^[77]^[78] Native iron primarily manifests as kamacite, a low-nickel alloy (typically 5-7% Ni), and taenite, a higher-nickel phase (up to 50% Ni), within iron meteorites. The Canyon Diablo meteorite in Arizona exemplifies this, comprising coarse-grained kamacite with embedded taenite lamellae and approximately 8% nickel overall, formed in the core of a differentiated asteroid. Telluric (terrestrial) native iron is exceptionally rare, with the largest known deposit on Disko Island, Greenland, where massive blocks up to 22 tons occur as inclusions in Paleocene basalts, resulting from magmatic reduction under low-oxygen fugacity conditions possibly involving carbon-rich xenoliths. This site hosts significant but uneconomic resources of native iron. Globally, native iron represents a negligible fraction of Earth's iron resources, far less than 0.1% compared to oxide ores like hematite.^[30]^[79]^[41] Nickel occurs natively as awaruite, a nickel-iron alloy (Ni₃Fe, ~75% Ni), formed during low-temperature serpentinization of ultramafic rocks in sulfur-poor, reducing environments that prevent sulfide formation. This process involves hydrogen generation from water-rock interactions, reducing dissolved nickel to metallic form. Key deposits include serpentinites in the Eastern Townships of Quebec, Canada, where awaruite grains up to several millimeters assay at 71% Ni, 25% Fe, and minor cobalt. While awaruite is reported in broader Canadian ultramafic terrains, including near Sudbury, Ontario, it is subordinate to sulfide ores there and not a primary economic target. Annual global production of native nickel remains negligible, overshadowed by vast sulfide and laterite resources.^[77]^[78]^[80] Native cobalt is among the rarest of these metals, typically alloyed with iron or nickel in meteorites or ultramafic settings rather than occurring in pure form, due to its strong affinity for arsenic and sulfur. Occurrences are documented in reduced environments like carbon-rich sediments or impact-related structures, but no significant terrestrial deposits exist; the Cobalt district in Ontario, Canada, is renowned for cobalt-bearing silver veins (e.g., cobaltite), not native metal. Meteoritic sources, such as those with ~3.5% cobalt in awaruite-like alloys, represent the primary known native cobalt.^[80]^[81] These native metals' formation underscores the role of extreme reducing conditions, including serpentinization, carbon-buffered volcanism, or extraterrestrial impacts, which deplete oxygen and allow metal segregation. Early human use highlights their rarity: beads from Gerzeh, Egypt (ca. 3200 BC), crafted from meteoritic iron with ~7.5% Ni and trace cobalt, mark the oldest known iron artifacts, predating widespread smelting by millennia. Today, native production for iron, nickel, and cobalt is virtually nonexistent, contributing negligibly to global supply.^[82]

Other Native Metals

Other native metals, beyond the more prominent examples like gold, silver, copper, and iron-group elements, occur infrequently in nature and typically in trace amounts or specialized geological environments. Bismuth, for instance, forms as native crystals within pegmatites and hydrothermal veins, with notable occurrences in China where it is associated with tungsten and tin mineralization in skarn and greisen deposits.^[83] Lead appears as rare masses, often in late-stage veins within major lead-zinc deposits; a significant example is the Broken Hill deposit in New South Wales, Australia, where native lead occurs in brines derived from oxidized fluids in a metamorphosed sedimentary host rock.^[84] Arsenic manifests in its native gray metallic form primarily as sublimates in volcanic fumaroles, such as those at oxidizing-type vents where arsenic volatilizes from magma and condenses directly as elemental metal, distinct from its sulfide mineral realgar.^[85] Cadmium, another scarce native metal, is sporadically reported in association with zinc ores, including sediment-hosted deposits in Greenland like the Mestersvig lead-zinc mine, though it rarely forms distinct elemental masses due to its strong affinity for sulfides.^[86] Molybdenum occurs natively in minor quantities within porphyry copper-molybdenum systems, exemplified by trace findings in the Climax and Henderson deposits in Colorado, where it appears as small grains in quartz-molybdenite veinlets amid granitic intrusions.^[87] Antimony forms native grains in epithermal vein systems, particularly in low-temperature hydrothermal settings like the Kharma deposit in Bolivia's Cordillera Oriental, where it coexists with stibnite and gold in quartz veins hosted by Paleozoic sandstones.^[88] These lesser-known native metals predominantly arise through secondary processes, such as supergene enrichment in oxidation zones or volcanic sublimation in fumarolic environments, rather than primary magmatic segregation. Their global production significance remains negligible, contributing less than 1% to overall metal output, as they are overshadowed by abundant sulfide and oxide ores that dominate commercial extraction. Unique instances include native tin, which is exceptionally rare and reported in small nuggets from greisen-related veins in Cornwall, United Kingdom, and native mercury, appearing as liquid droplets from the thermal decomposition of cinnabar in the Almadén deposit, Spain, where high-temperature fluids volatilize mercury sulfide to yield elemental mercury upon cooling.^[89]^[90]

Extraction and Uses

Extraction Methods

Native metals, occurring in elemental form without chemical combination, are extracted using methods that leverage their physical properties like density and malleability, often requiring less intensive processing than sulfide ores. These techniques range from artisanal practices to industrial operations, primarily targeting placer deposits for gold and silver, and vein or massive deposits for copper and platinum group metals. Extraction focuses on separating the metal from surrounding gangue materials, with efficiency depending on deposit type and scale. Traditional methods for recovering native metals from placer deposits, such as those prominent during 19th-century gold rushes, include panning and sluicing. Panning involves swirling sediment in a shallow pan with water to allow denser native gold particles to settle at the bottom, a labor-intensive technique effective for small-scale operations in rivers and streams. Sluicing extends this by channeling water over a series of riffles in a long trough, trapping heavy native metal nuggets and flakes while lighter materials wash away; this method was widely used in California's 1849 Gold Rush, processing larger volumes of gravel. For native copper, open-pit mining was employed in Michigan's Keweenaw Peninsula starting in the mid-19th century, where miners used hand tools and later steam-powered equipment to quarry large, pure masses from bedrock exposures, exploiting the metal's softness for easy detachment. Modern extraction techniques for native metals emphasize mechanical and chemical separation to handle low-grade deposits efficiently. Gravity separation, using jigs, shaking tables, or centrifugal concentrators, exploits the high density of native metals like gold (specific gravity ~19.3) to separate nuggets and fine particles from alluvial gravels, achieving recovery rates up to 95% in optimized plants. For low-grade native ores, heap leaching applies dilute cyanide solutions to crushed rock piles, dissolving gold or silver for subsequent recovery via carbon adsorption; this method is cost-effective for disseminated native grains, as seen in Nevada's Carlin-type deposits. If native metals occur with sulfides, froth flotation precedes, where collectors attach to mineral particles, creating a froth concentrate for further refining, though pure native forms often bypass this step. Challenges in native metal extraction include environmental contamination and the need for impurity removal. Artisanal gold mining frequently employs mercury amalgamation to capture fine native particles, but this releases toxic mercury into waterways, affecting ecosystems and human health in regions like sub-Saharan Africa and South America, with global estimates of 1,000-3,000 tonnes of mercury used annually. Refining native alloys like electrum (gold-silver mix) involves parting with nitric acid or electrolysis to separate components, ensuring purity for commercial use. These issues drive regulations, such as the Minamata Convention on Mercury, to phase out harmful practices. Economically, native metals benefit from minimal beneficiation needs, lowering extraction costs compared to refractory ores; for instance, placer gold requires only concentration and smelting, reducing energy use by up to 50%. Globally, approximately 90% of gold production derives from lode deposits containing native metal components, often combined with heap leaching or milling, underscoring their role in sustaining supply amid rising demand.

Historical and Modern Uses

Native metals have played a pivotal role in human history due to their rarity and malleability, allowing early civilizations to utilize them with minimal processing for practical and symbolic purposes. In ancient Lydia around 600 BCE, native gold, often in the form of electrum—a natural alloy of gold and silver—was minted into the world's first coins, revolutionizing trade and establishing a standardized medium of exchange.^[91] Native copper, valued for its workability, was hammered into tools such as axes during the Neolithic and early Chalcolithic periods (circa 5000–3500 BCE), marking one of the earliest transitions from stone to metal implements in regions like the Near East and Europe.^[92] Similarly, silver was crafted into tableware and utensils by the Romans, where wealthy households used silver plates and vessels not only for dining but also for their perceived antimicrobial properties to store liquids and ward off disease.^[93] In modern applications, native metals continue to underpin key industries, leveraging their inherent purity and conductivity without extensive refinement. Gold extracted from native sources meets approximately 5% of global demand through electronics as of 2024, where it is used in connectors, circuit boards, and sensors for its corrosion resistance and reliable performance in devices like smartphones and computers; trends remained stable into 2025.^[94]^[95] Platinum from native deposits satisfies around 40% of its total demand in autocatalysts, essential for reducing harmful emissions in vehicle exhaust systems and supporting environmental regulations worldwide.^[96] Native copper contributes to roughly 50% of global copper usage in electrical wiring and cabling, powering infrastructure from power grids to telecommunications due to its superior electrical conductivity.^[97] The economic significance of native metals is substantial, with the global precious metals market—dominated by gold—valued at over $300 billion annually, reflecting their enduring appeal in investment and fabrication.^[98] Native gold is frequently incorporated into alloys such as white gold, which combines pure gold with metals like nickel or palladium to achieve a durable, silvery finish for jewelry and other items. Culturally, these metals persist in jewelry, accounting for about 38% of gold demand as of 2024, and as collectibles, where unrefined native nuggets of gold or copper are prized by enthusiasts for their natural formations and historical authenticity.^[94]

References

[1]
9.2.1: Native Elements- Metals, Semimetals, and Nonmetals
Aug 28, 2022 · Within the metal group, the principal native minerals are gold, silver, copper, and platinum. These four minerals all contain weak metallic ...Missing: definition | Show results with:definition
[2]
Mineral Mondays: Native Elements - California Academy of Sciences
Sep 26, 2016 · They are composed of three groups: metals, semimetals, and nonmetals. Notable examples include gold and copper, both of which are metals; ...
[3]
[PDF] Economic Geology of the Platinum Metals
The native platinum metals, found mainly in placer deposits, consist ... of native platinum metals as a byproduct of gold mining. This output, though ...<|separator|>
[4]
Statistical Compendium | U.S. Geological Survey - USGS.gov
Along with gold and silver, they are known as precious or noble metals. They occur as native alloys in placer deposits or, more commonly, in lode deposits ...
[5]
https://www.gemsociety.org/article/introduction-to-native-elements/
[6]
Introduction to Native Elements - International Gem Society
Jan 4, 2025 · Native element minerals are defined as single-element minerals or naturally occurring metallic alloys. Of the 118 known elements featured on ...
[7]
An Introduction to Native Metals
### Summary of Native Metals
[8]
An Introduction to Geology: 2.21 | OpenLearn - The Open University
The simple answer is that these metals, and a few others, occur in their 'native forms' – as a naturally occurring piece of metal, not combined with other ...
[9]
Gold
Density @ 293 K: 19.32 g/cm3. Ground State Electronic Configuration: Electron config. : [Xe] 4f14 5d10 6s1. Color: Yellow in mass; however, when it is finely ...
[10]
Platinum | Pt | CID 23939 - PubChem - NIH
Density: 21.45 g cm-3 at room conditions (very dense). Also shipped as a finely divided powder (platinum black), as a sponge, and as particles deposited on ...
[11]
Density for Some Select Substances - gchem
Density for Some Select Substances ; silver, 10.50 ; sodium, 0.970 ; styrofoam, 0.075 ; steel, 8.05.
[12]
14.2: Native Elements - Geosciences LibreTexts
Aug 28, 2022 · Gold, silver, platinum, and copper are the most common of the native metals. Additionally, iron, zinc, nickel, lead, and indium have occasionally been reported.Missing: definition | Show results with:definition
[13]
metal - The Worlds of David Darling
Malleability and ductility are further metallic characteristics. Gold is the most malleable of all metals; it can be beaten so thin as to be virtually ...
[14]
Scientific Properties of Precious Metals - APMEX
May 24, 2022 · Of all precious metals, gold is the softest in terms of malleability. Silver. Silver. Symbol, Ag. Atomic Number, 47. Density (g/cm-3) ...Missing: physical native
[15]
[PDF] APPENDIX H Standard Reduction Potentials* - CSUN
*All species are aqueous unless otherwise indicated. The reference state for amalgams is an infinitely dilute solution of the element in.
[16]
A New Occurrence of Terrestrial Native Iron in the Earth's Surface
Jul 31, 2018 · Examples of elements present in the native (zero-valence) state include, among others, Al [1,2], Si [3], Ni [4], Au [5,6], Co [7], Cu and Ti [8] ...
[17]
Electrum Metal Alloy or Green Gold - ThoughtCo
Jun 10, 2025 · Electrum is a natural alloy of gold and silver, often with copper, platinum, or other metals. Man-made versions are called green gold.
[18]
Electrum - an overview | ScienceDirect Topics
Electrum is a natural alloy of gold and silver, with silver content between 15% and 50%, and is one of the seven known metals.
[19]
Copper: An Ancient Metal - Sites at Dartmouth
Archaeological evidence suggests that copper was first used between 8,000 and 5,000 B.C., most likely in the regions known now as Turkey, Iran, Iraq and — ...
[20]
Exceptionally high levels of lead pollution in the Balkans from the ...
May 29, 2018 · The earliest use of metals in the form of native copper in Anatolia roughly 9,000 y before common era (BCE) (2) preceded the invention of ...
[21]
Gold - USGS Publications Warehouse
Jun 24, 1997 · Gold was among the first metals to be mined because it commonly occurs in its native form, that is, not combined with other elements ...
[22]
Silver Mining in History
The story of silver mining began about 5,000 years ago. Silver was first mined around 3,000 BCE in Anatolia, now located in modern-day Turkey.
[23]
The Structure of Prices in the Neo-Sumerian Economy (I): Barley ...
The shekel of silver was the basis of valuing all commodities in the Ur III accounts with the prescribed norm of 1 shekel = 300 sila3 (“liters”) of barley as ...
[24]
Early copper production by the last hunter-gatherers - ScienceDirect
... evidence for casting in Anatolia comes from Yumuktepe, dating to around 5000 BCE (Yalçın, 2000). Although cold working of native copper was observed in Çayönü ...
[25]
COPPER (CHALCOLITHIC) AGE (4500 to 3500 B.C.)
The 1,000-year-long Copper Age lasted from about 4500 B.C. to 3500 B.C., overlapping with the early Bronze Age. Some cultures and individuals used Copper Age ...
[26]
[PDF] Gone Platinum: Contraband and Chemistry in Eighteenth-Century ...
Mar 14, 2011 · Pre-Hispanic platinum alloys: Their composition and use in Ecuador and Colombia. In Archaeometry of pre-Columbian sites and artifacts, eds.
[27]
Ancient Platinum Technology in South America,” Platinum Metals ...
The early inhabitants of South America had recognised platinum and had used i t for making ornaments well before the Spanish Conquest.
[28]
[PDF] a summary of ideas on the origin of native copper deposits1
the reduction of copper was effected by ferrous salts in hydrothermal solutions. The similar characteristics of all the native copper occurrences in ultra ...<|separator|>
[29]
Native nickel in the TAG hydrothermal field sediments (Mid‐Atlantic ...
May 31, 2006 · Serpentinization results in the generation of highly reduced volatile species: H2 and hydrocarbons. In such an extremely reduced environment, Fe ...
[30]
[PDF] 12. Supergene Ore and Gangue Characteristics
Supergene ore and gangue minerals result from reactions between hypogene sulfides and acidic meteoric waters, forming a copper-rich enrichment over a gossan.
[31]
Metallography of Iron-Nickel Meteorites - Vacaero
Jun 5, 2018 · Iron meteorites are Fe-Ni alloys with nickel contents ranging from about 4.3 to 34 weight %. Most, however, have nickel contents from about 5 to 10%.
[32]
[PDF] The thermochemistry of gold - SciSpace
It is the only metal that is stable at room temperature in air. The Gibbs energy of formation of gold oxide,. Au2O,, may be represented (1) by the equation ...
[33]
Tectonic Settings of Metal Deposits - Geology In
Tectonic Settings of Metal Deposits · Geological processes operating due to energy released at plate boundaries control the process of mineral deposition.
[34]
[PDF] Descriptive Models for Epithermal Gold-Silver Deposits
Epithermal gold-silver deposits are shallowly formed vein, stockwork ... Most epithermal deposits are related to hydrother- mal systems that form in ...
[35]
Epithermal - Earth Sciences New Zealand | GNS Science | Te Pῡ Ao
Epithermal deposits develop from metal-rich hydrothermal fluids that rise from deep magmatic sources. As these fluids ascend and interact with cooler ...
[36]
Epithermal Deposit - an overview | ScienceDirect Topics
Epithermal deposits are defined as products of magmatic-hydrothermal activity that form in near-surface environments, serving as important sources of gold, ...
[37]
[PDF] Quartz-pebble-conglomerate gold deposits
May 14, 2018 · The granite basement has relatively low density, around 2.63 grams per cubic centimeter (g/cm3). ... The most significant of these are native gold ...<|separator|>
[38]
The Origin of Gold in South Africa | American Scientist
Nearly half the gold ever mined in human history has come from these conglomerates in South Africa's Witwatersrand basin.
[39]
[PDF] Platinum-Group Elements in Southern Africa—Mineral Inventory and ...
This report assesses the mineral inventory and undiscovered mineral resources of platinum-group elements in Southern Africa.
[40]
Age of native copper mineralization, Keweenaw Peninsula, Michigan
Amygdaloidal flood basalts and conglomerates are the host for substantial deposits of native copper within the Portage Lake Volcanics in the Keweenaw ...Missing: flows | Show results with:flows
[41]
Copper Isotope Constraints on the Genesis of the Keweenaw ... - MDPI
The Keweenaw Peninsula native copper district of Michigan, USA is the largest concentration of native copper in the world.
[42]
Petrogenesis of Uivfaq Iron, Disko Island, Greenland - AGU Journals
Dec 10, 1981 · Massive blocks of native iron and iron carbide, weighing up to 22 tons, have been found at Uivfaq, Disko Island, western Greenland.
[43]
Extraterrestrial native iron in deep-water sediments of the NW Atlantic
Mar 5, 2015 · The global pattern of Ni distribution in the native iron is emphasized by similarity of bar charts for the Atlantic and Eurasian sediments.
[44]
[PDF] Gold in Minerals and the Composition of Native Gold
It forms complete series of solid solu- tions with silver, copper, nickel, palladium, and platinum. In association with the platinum metals, gold occurs as free ...
[45]
Gold - Geoscience Australia
May 14, 2025 · When gold is found in rocks it is almost always in a pure state. Large pieces of gold are called nuggets and tiny pieces are known as gold dust.<|separator|>
[46]
Where is all the gold? - SciELO South Africa
Apr 19, 2023 · Compiled data from 1887 to 2019 shows that 50 200 t of gold were produced by Witwatersrand mines, while it is estimated that a further 48 100 t ...
[47]
The origin and evolution of the Klondike goldfields, Yukon, Canada
Gold placer deposits are mostly alluvial genesis deposits and of Quaternary to Oligocene (?) age. The alluvial deposits consist of gravel with pebbles ...
[48]
Factors in the formation of the giant Kalgoorlie gold deposit
Kalgoorlie (Golden Mile plus Mt Charlotte) accounts for more than half the gold won from the 2000 deposits that comprise the widespread gold mineralization ...
[49]
Electrum, the Gold–Silver Alloy, from the Bulk Scale to the Nanoscale
The term “Electrum” denotes the native gold–silver alloy that provided humanity with some of its first experiences with metallurgy. Its surface abundance in ...
[50]
Gold‐quartz veins in metamorphic terranes and their bearing on the ...
Jul 10, 1995 · Gold-quartz vein fields in metamorphic terranes such as greenstone belts provide evidence for the involvement of large volumes of fluids during faulting.
[51]
Gold | Volcano World - Oregon State University
Gold is most commonly found along the edges of greenstone belts and associated with structural features. Intensely altered and fractured basalt is a common ...
[52]
Gold facts - Natural Resources Canada
Mar 13, 2025 · Global gold mine production was estimated at 3,000 tonnes in 2023, almost equivalent to 2022 production. The top five gold-producing countries ...
[53]
Trace elements in native gold by solution ICP-MS and their use in ...
Aug 5, 2025 · ... silver content of the gold being less than 15 percent. In contrast, populations of alluvial gold from the Grampian and Highland terranes ...
[54]
Silver: A native element, mineral, alloy, and byproduct - Geology.com
Unlike gold, it is rarely found in significant amounts in placer deposits. Native silver is sometimes found in the oxidized zones above the ores of other metals ...
[55]
Spectacular Native Silver: Rarer Than Gold - Rock & Gem Magazine
Dec 3, 2024 · Native silver specimens are rarer than native gold specimens. Actually, we have found gold in more or less pure form ever since humans picked up the first ...Visiting The Silver Vault · Native Silver At The... · Dynamic Deposits<|separator|>
[56]
Supergene Silver Enrichment Reassessed | GeoScienceWorld Books
Jan 1, 2009 · The results of this preliminary analysis show that only 12 (30%) of the deposits contain(ed) appreciable amounts of silver ore generated by silver sulfide ...
[57]
[PDF] Mineralogy, Mineral Chemistry, and Paragenesis of Gold, Silver, and ...
An older gold-bearing association consists of two fine-grained ore stages, both of which contain electrum, uytenbogaardtite, tetrahedrite, silver sulfo- salts, ...
[58]
[PDF] Silver - Mineral Commodity Summaries 2024 - USGS.gov
Mar 5, 2024 · Silver was produced in 12 States, and Alaska continued as the country's leading silver-producing State, followed by Nevada. There were 24 U.S. ...
[59]
[PDF] Platinum-Group Elements - USGS Publications Warehouse
found grains of these alloys mingled with gold nuggets they recovered from stream deposits in the same area; they called the metal “platina” (McDonald and ...
[60]
Native Platinum: Mineral information, data and localities.
True native platinum in the mineralogical species sense is a rather rare mineral, and most of the specimens so labelled are in fact isoferroplatinum.
[61]
[PDF] ORIGIN OF PLATINUM-GROUP-MINERAL NUGGETS INFERRED ...
Several grains of isoferroplatinum and of Os-Ir-Ru alloys were subjected to the examination of Re contents, including an iridian osmium grain that displays the.
[62]
Origin of platinum-group mineral nuggets inferred from an osmium ...
Aug 5, 2025 · Most Alpine+ype samples are Os-Ir-Ru alloys, and most Alaskan-type samples are Pt-Fe alloys (isoferroplatinum or tetraferroplatinum), which ...
[63]
[PDF] Platinum-Group Metals 2021 - USGS Publications Warehouse
Apr 13, 2025 · in 2021, world mine production of PGms increased by 12% to 472,000 kg from 422,000 kg (revised) in 2020 (tables 1, 5). south africa accounted ...
[64]
Mineralogy and mineral chemistry of detrital platinum-group ... - EJM
Jul 6, 2023 · This showed that Pt–Fe alloys are (1) native platinum (> 80 atom %), (2) ferroan Pt (20 atom % to 50 atom % Fe), (3) isoferroplatinum (2.64 to ...<|separator|>
[65]
[PDF] Platinum-Group Elements in Sedimentary Environments in the ...
Platinum-group elements (PGE) have long been pro- duced from placer deposits, particularly those in the Ural. Mountains of Russia and in Colombia, and more ...
[66]
[PDF] Magmatic Ore Deposits in Layered Intrusions—Descriptive Model for ...
This report describes a model for magmatic ore deposits in layered intrusions, specifically reef-type PGE and contact-type Cu-Ni-PGE deposits.
[67]
Petrogenesis of the Platinum-Group Minerals - GeoScienceWorld
Jan 1, 2016 · These detrital PGM have generally been sampled in chromite-rich beach sands ... deposit (Volkovsky complex, Central Urals, Russia) . Miner Petrol.
[68]
Origin and depositional history of platinum-group minerals in placers
The present work reviews assemblages of detrital platinum-group minerals (PGM) in placers worldwide with the aim of identifying common and distinctive ...<|separator|>
[69]
Copper deposits of the western Upper Peninsula of Michigan
Jan 1, 2011 · The Keweenaw Peninsula native copper district produced 11 billion lbs of copper and a lesser unknown but significant quantity of silver. Native ...
[70]
Michigan Copper - Michiganology
After the Civil War, copper mining in the Keweenaw expanded. For forty years (1847-1887), Michigan produced more copper than any state in the nation.
[71]
Copper - Etymology, Origin & Meaning
Originating from late Old English and Latin Cyprium (from Greek Kyprios "Cyprus"), "cop" means a malleable metal or a policeman who seizes or arrests.
[72]
Edom's Copper Mines in Timna: Their Significance in the 10th Century
Aug 12, 2018 · Copper has been mined in the Timna Valley since the 5th millennium B.C.E. Recent excavations reveal that activity in the region peaked in ...Missing: 5000 | Show results with:5000<|separator|>
[73]
[PDF] Grade and Tonnage Relationships Among Copper Deposits
In this study, the grades and tonnages of three types of copper deposits are compared with theore- tical statistical models in order to build models of future ...
[74]
Concentration of Metals Associated with the Native Copper Deposits ...
The Keweenaw Peninsula of northern Michigan is home to the largest accumulation of native copper in the world. Native copper deposits are hosted in the 1.1 ...
[75]
(PDF) The Anthropology of Native Copper Technology and Social ...
1980). Native copper is noted for its purity, which is often greater than 99.9% ... cold-working experiment on native copper and found that the thickness of ...
[76]
New Understandings About Michigan's Old Copper Complex
Mar 4, 2025 · Now studies show this enigmatic complex existed by at least 6,000 B.C., if not earlier, making it one of the oldest metallurgical traditions in ...
[77]
Awaruite: Mineral information, data and localities.
Occurs in chromitite associated with ultramafic igneous rocks, also in river placers from serpentinized peridotites and ophiolites. Awaruite is rare in ...
[78]
Formation and Preservation of Brucite and Awaruite in ...
Awaruite formed during both late lizardite serpentinization and during antigorite serpentinization and is most abundant in serpentinized olivine-rich ...
[79]
The Canyon Diablo Meteorite - Astrophysics Data System
In kamacite at its boundaries with taenite, the Ni-content of the Canyon Diablo meteorite is reduced, while in taenite at its boundaries with kamacite it is ...Missing: native | Show results with:native
[80]
[PDF] Disko Island (Greenland) - Natural Analogues
Native iron is hosted in basaltic volcanic formations which cover more that 90 % of the area of the island, and the estimated iron resources are about 5 Million ...
[81]
[PDF] the occurrence of native nickel-iron in the serpentine rock of the ...
ABSTRACT ,. Native nickel-iron has been found over a wide area in the serpentinized asbestos- bearing rock of the Eastern Townships of Quebec.
[82]
Geological history of Cobalt | Earth Sciences Museum
Cobalt is a small mining town in Ontario which is well-known for its large deposits of silver, and has a very interesting geologic history.
[83]
5,000 years old Egyptian iron beads made from ... - UCL Discovery
The earliest known iron artefacts are nine small beads securely dated to circa 3200 BC, from two burials in Gerzeh, northern Egypt. We show that these beads ...
[84]
Bismuth: Economic geology and value chains - ScienceDirect.com
Bismuth minerals, such as bismuthinite and native bismuth, are reported in 23% of global Au-dominant skarn deposits and in 9% of skarn deposits where Au is a by ...
[85]
[PDF] NATIVE LEAD AT BROKEN HILL, NEW SOUTH WALES, AUSTRALIA
Native lead, a rare mineral, occurs in a late-stage vein in the world's largest lead – zinc – silver deposit, at Broken Hill,. Australia.
[86]
Fumarolic arsenates − a special type of arsenic mineralization
Mar 1, 2018 · This paper is a review devoted to a special type of arsenic mineralization related to volcanic fumaroles of the oxidizing type.
[87]
[PDF] Environmental Impact of the Lead-Zinc Mine at Mestersvig, East ...
These studies showed that cadmium and copper were not elevated in marine biota, and that zinc was only elevated in seaweed, whereas lead was elevated in several ...
[88]
[PDF] Arc-Related Porphyry Molybdenum Deposit Model
Molybdenite in porphyry deposits may be a source for rhenium because molybdenite is the only major sulfide with substantial quantities of rhenium within its ...<|control11|><|separator|>
[89]
The composite gold-antimony vein deposit at Kharma (Bolivia)
Mar 2, 2017 · The Kharma antimony deposit in the Cordillera Oriental, Bolivia, is representative of vein-type antimony deposits that have stibnite as the only mineral of ...
[90]
[PDF] Antimony - USGS Publications Warehouse
Aug 17, 2025 · The Cordillera Oriental in Bolivia contains more than. 500 known antimony-gold deposits, which are typified by the Kharma deposit. The Kharma ...
[91]
Exposure to mercury in the mine of Almadén - PMC - PubMed Central
In Almadén, small drops of native mercury can be observed embedded in the cinnabar walls in most of the mines. The deposits are vertically oriented, the width ...
[92]
[PDF] Weighing or counting in ancient Greece: the first coins.
Sep 9, 2024 · The very economically advanced societies in Mesopotamia, Egypt and the Levant, had already used weighed gold, silver and copper, alongside other ...
[93]
Copper and Bronze: The Far-Reaching Consequences of Metallurgy
The first implements made of copper were daggers, probably for ritual and not practical use. Such daggers have been found in Beycesultan and Alaca Hüyük, both ...
[94]
Silver: Metal of Many Faces - Sites at Dartmouth
It was used as currency, gifts, jewelry, and in drinking and eating utensils. A family's status, wealth and social prominence was shown by its visible display ...Missing: tableware | Show results with:tableware
[95]
Gold Demand Trends: Full Year 2024
### Summary of Gold Demand by Sector for 2024
[96]
Demand Drivers - About Platinum
It has been between 29-42% of total demand in the last five years. Autocatalysts. Platinum is central to reducing vehicle emissions in vehicles, which must ...
[97]
Copper Statistics and Information | U.S. Geological Survey - USGS.gov
Statistics and information on the worldwide supply of, demand for, and flow of the mineral commodity copper.
[98]
Precious Metals Market Size, Share, Growth Analysis, 2032
The global precious metals market size was $306.44 billion in 2023 & is projected to grow from $323.71 billion in 2024 to $501.09 billion by 2032.