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Zircon

Zircon is a zirconium silicate mineral with the chemical formula ZrSiO₄, serving as the principal economic source of the element zirconium and often containing trace amounts of hafnium.^[1] It is a hard, chemically stable nesosilicate that commonly occurs as an accessory mineral in igneous, metamorphic, and sedimentary rocks, particularly in heavy-mineral sands derived from the weathering of such rocks.^[2] Zircon typically forms tetragonal prismatic crystals with a vitreous to adamantine luster, exhibiting a Mohs hardness of 7.5 and a specific gravity of 4.6 to 4.7.^[3] Its color varies widely, from colorless and transparent varieties prized as gemstones to brown, red, yellow, or green hues influenced by impurities like iron or uranium; colorless zircon, with its high refractive index of 1.81–1.99, can resemble diamond when cut as jewelry.^[4] Due to its resistance to weathering, abrasion, and chemical alteration, zircon persists in sedimentary deposits and is a common component of sands worldwide.^[5] The mineral's industrial applications are extensive, including use as a refractory material in high-temperature furnaces, opacifier in ceramics and glazes, and foundry sand for molding metals, owing to its thermal stability up to 2,550 °C and low thermal expansion.^[6] Zircon is also the primary ore for extracting zirconium metal, which is employed in nuclear reactors for fuel cladding due to its low neutron absorption, as well as in chemical processing equipment for corrosion resistance.^[1] In gemology, heat-treated zircon enhances its color and clarity, making it the traditional birthstone for December.^[4] Beyond industrial and ornamental uses, zircon plays a pivotal role in geochronology, particularly uranium-lead (U-Pb) dating, as its crystal structure incorporates uranium and thorium while excluding lead, allowing precise age determination of geological events.^[7] The oldest known zircon grains, found in Western Australia's Jack Hills, date to approximately 4.4 billion years ago, providing insights into Earth's early crust formation.^[8] Global production of zircon concentrates, primarily as a byproduct of titanium and tin mining, reached about 1.5 million metric tons in 2024, with major producers including Australia, South Africa, and other countries such as the United States.^[9]

Etymology and History

Name Origin

The name "zircon" derives from the Persian word zargun, meaning "gold-colored" or "gold-hued," alluding to the mineral's frequent golden to orange-brown tones. This etymology reflects the stone's historical appreciation for its warm, lustrous appearance in ancient Persian and Arabic cultures.^[10]^[11] An alternative origin traces the term to the Arabic zarkūn or zarkun, signifying "vermilion" or "cinnabar," which may refer to the reddish varieties of zircon known in early trade routes. The word likely traveled through Arabic intermediaries from Persian roots, as early Islamic scholars like Al-Biruni documented similar gems under names evoking fiery or golden colors in the 11th century. This linguistic evolution highlights zircon's role in pre-modern gemology across the Middle East and South Asia.^[10]^[11] In Europe, the name entered scientific nomenclature in the late 18th century. German chemist Martin Heinrich Klaproth coined "zirconium" for the element he isolated from the mineral in 1789, adapting the German Zirkon from French circon or jargon—an older term for translucent gemstones borrowed from Medieval Latin jargōn, possibly sharing the same Perso-Arabic source. Prior to this, zircon was often called "hyacinth" or "jacinth" in Western texts, distinguishing it from other colored zircons labeled as "jargoon."^[11]

Historical Uses

Zircon has been valued as a gemstone for over two millennia, with evidence of its use dating back to ancient civilizations in South Asia. Gem-grade zircon was extracted from river deposits in regions such as Sri Lanka, where mining has occurred for hundreds of years, and it is referenced in ancient Sanskrit texts as a prized stone associated with light and prosperity.^[12] These early applications primarily involved crafting jewelry and ornamental objects, leveraging the mineral's high refractive index and dispersion for its brilliant sparkle.^[13] During the Middle Ages in Europe, zircon gained prominence in jewelry for its perceived mystical properties, believed to induce sound sleep, repel evil spirits, and foster wealth, honor, and wisdom. Blue and colorless varieties were particularly favored, often incorporated into rings, necklaces, and talismans by nobility and clergy. This period marked a shift toward more widespread use in Western adornment, though zircon was sometimes confused with other gems like jacinth due to similar appearances.^[10] By the 19th century, colorless zircon emerged as a popular, affordable substitute for diamond in Victorian-era jewelry, prized for its diamond-like fire and cut into brilliant facets to mimic the pricier stone. Artisans in Europe and America frequently employed it in everyday pieces, enhancing accessibility to sparkling gems amid the era's industrial expansion. However, its use declined with the advent of synthetic alternatives, though historical pieces remain collectible for their optical qualities.^[14]

Chemical and Physical Properties

Composition and Crystal Structure

Zircon, with the ideal chemical formula ZrSiO₄, is a zirconium orthosilicate mineral composed of one zirconium cation (Zr⁴⁺) and one isolated silicate tetrahedron (SiO₄^4-). The molecular weight is 183.31 g/mol, reflecting the stoichiometric ratio of Zr:Si:O as 1:1:4. In natural specimens, the composition is typically close to ideal but exhibits variability due to trace substitutions; hafnium (Hf⁴⁺) commonly replaces Zr⁴⁺ at levels up to 1-2 wt%, while rare earth elements (REE³⁺), yttrium (Y³⁺), phosphorus (P⁵⁺), and calcium (Ca²⁺) can occupy the Zr site or couple with charge-balancing defects on the Si or O sites. These substitutions influence the mineral's stability and properties, with Hf content often correlating to geological provenance.^[15]^[16] The crystal structure of zircon is tetragonal, belonging to the space group I4₁/amd (No. 141), with four formula units (Z = 4) per unit cell. Unit cell parameters are approximately a = 6.607 Å and c = 5.982 Å at ambient conditions, yielding a volume of about 261 Å³. The structure is characterized by infinite chains parallel to the c-axis, formed by alternating edge-sharing SiO₄ tetrahedra and ZrO₈ polyhedra (bisdisphenoids or distorted triangular dodecahedra). Each Si⁴⁺ is tetrahedrally coordinated to four O^2- atoms with bond lengths around 1.62 Å, while each Zr⁴⁺ bonds to eight O^2- atoms at average distances of 2.27 Å. Adjacent chains are linked laterally by corner-sharing, creating a three-dimensional framework with open channels along the c-axis that can accommodate radiation damage or metamictization in natural samples.^[17]^[18] This zircon-type structure is archetypal for island silicates, providing rigidity through the isolated tetrahedra and the highly coordinated Zr polyhedra, which contribute to the mineral's resistance to weathering and high melting point. Under high pressure, zircon can transform to denser phases like scheelite-type (P4₁/nmm) at around 170 kbar, where Si adopts octahedral coordination, but the ambient tetragonal form dominates in natural occurrences. Variations in composition, such as increased REE content, can slightly expand the unit cell due to larger ionic radii, as observed in xenotime-like end-members (YPO₄) within the zircon group.^[19]^[20]

Physical and Optical Characteristics

Zircon (ZrSiO₄) crystallizes in the tetragonal system, typically forming prismatic or pyramidal crystals that can be elongated or stubby, with well-developed prism and pyramid faces.^[3] Its hardness varies from 6 to 7.5 on the Mohs scale, with high-type (crystalline) specimens reaching 7.5 due to their intact structure, while metamict (radiation-damaged) varieties are softer at around 6.^[13] Specific gravity ranges from 3.90 to 4.73, higher in undamaged crystals (4.6–4.7) and lower in metamict forms owing to structural degradation from incorporated uranium and thorium decay.^[13] Cleavage is indistinct on {110}, and fracture is conchoidal to uneven; the mineral exhibits a white streak and is brittle.^[21] Luster is adamantine to subadamantine, contributing to its gem-like brilliance, and transparency spans transparent to translucent, though opaque grains occur in some metamict samples.^[22] Colors are diverse, including colorless, yellow, brown, orange, red, green, and blue, often resulting from trace elements or radiation-induced defects; in thin section, it appears colorless to pale brown.^[3] Optically, zircon is uniaxial positive, with refractive indices varying significantly based on degree of metamictization: high-type specimens show ω = 1.920–1.925 and ε = 1.984–1.990, intermediate types 1.875–1.905, and low-type nearly isotropic at 1.810–1.815.^[13] Birefringence ranges from 0.000 in heavily damaged, amorphous-like low types to 0.059 in pristine high types, producing strong double refraction visible as doubling of crystal edges.^[13] Dispersion is notably high at 0.039, exceeding that of diamond and responsible for vivid fire (spectral color flashes) in faceted gems.^[23] Pleochroism is weak to distinct in colored varieties, showing differences in absorption along optic axes, such as yellowish-brown to reddish in brown specimens.^[24] In petrographic thin sections, zircon displays very high relief and high-order interference colors under crossed polars, aiding identification in igneous and metamorphic rocks.^[25] Metamictization, caused by alpha decay of radioactive impurities, progressively alters these properties: high types retain full tetragonal symmetry and optimal values, while low types approach isotropy with reduced density, refractive index, and birefringence, sometimes appearing greenish or brownish due to hydration.^[13] Heat treatment can partially reverse damage in low types, restoring higher optical properties and clarity.^[13]

Geological Aspects

Natural Occurrence

Zircon (ZrSiO₄) is a common accessory mineral occurring in trace amounts within a wide range of igneous, metamorphic, and sedimentary rocks worldwide.^[26] It typically forms as microscopic crystals or grains during the crystallization of magma in felsic igneous rocks such as granites and pegmatites, or through metamorphic processes in high-grade terrains.^[12] Due to its exceptional durability and resistance to chemical weathering, zircon grains are often preserved and concentrated in sedimentary environments, particularly in heavy mineral sands derived from eroded source rocks.^[7] Significant natural concentrations of zircon are found in placer deposits and beach sands, where it accumulates alongside other dense minerals like rutile and ilmenite. In Australia, zircon is abundant in ancient sedimentary basins and coastal heavy mineral sands, with notable occurrences in Western Australia (e.g., the Eucla Basin) and eastern states like New South Wales and Queensland, often associated with alkaline basalts.^[12] Africa hosts major deposits in Mozambique and South Africa, where zircon forms in alluvial and coastal sands from Precambrian basement rocks, contributing to some of the world's largest reserves.^[27] Gem-quality zircon crystals occur naturally in alluvial gravels and metamorphic terrains in Southeast Asia and the Indian Ocean region. Prominent localities include river and beach deposits in Sri Lanka, Myanmar (Burma), and Thailand, where waterworn pebbles yield transparent varieties in colors ranging from colorless to deep red or blue.^[28] Madagascar also produces high-quality zircon from alkali-rich pegmatites and metamorphic gneisses, often featuring heat-treated stones that enhance their natural hues.^[29] The mineral's ubiquity and resilience make it a key component of the Earth's crust, with detrital grains in sands and soils providing insights into ancient geological events; for instance, the oldest known zircon crystals, dated to approximately 4.4 billion years, were discovered in Western Australia's Jack Hills metaconglomerate, representing Hadean-era crustal remnants.^[30]^[31]

Formation Processes and Varieties

Zircon (ZrSiO₄) primarily forms as an accessory mineral during the crystallization of felsic magmas, such as those producing granites and rhyolites, typically at temperatures of 700–900 °C.^[32]^[33] These crystals develop as the magma cools slowly, incorporating trace elements like uranium and thorium, which later influence their properties through radioactive decay. In such settings, zircon often appears as small, euhedral prisms resistant to alteration, preserving records of magmatic events.^[34] In metamorphic environments, zircon often forms through solid-state reactions or recrystallization, particularly during retrograde processes at temperatures around 600–700 °C, where hydration reactions promote growth as overgrowths on pre-existing grains.^[35]^[36] Prograde conditions may resorb zircon through the breakdown of Zr-bearing phases like baddeleyite or the mobilization of zirconium in fluids, leading to new rims or entire crystals that record metamorphic ages. Zircon's durability allows it to survive high-grade metamorphism, often retaining cores from earlier igneous origins while adding metamorphic layers.^[12] Detrital zircons, derived from the erosion of igneous or metamorphic source rocks, accumulate in sedimentary deposits such as sandstones, conglomerates, and placer environments, where they concentrate due to their high density (specific gravity 4.6–4.7).^[12] These grains can undergo transport over vast distances and burial, yet remain chemically stable, making them key for provenance studies. Economic deposits, like heavy mineral sands in Australia, form through repeated cycles of weathering, erosion, and deposition over millions of years.^[12] Zircon varieties are classified based on color, crystal habit, and degree of radiation-induced metamictization, which alters the lattice structure over geological time due to alpha decay of incorporated uranium and thorium. High zircon exhibits an intact tetragonal crystal structure with standard properties, including a refractive index of 1.92–1.98, birefringence up to 0.059, and strong dispersion (0.039), often appearing as colorless, yellow, or red gems.^[13]^[37] Intermediate zircon shows partial metamictization, with slightly reduced optical properties (refractive index 1.81–1.90) and a transitional structure, commonly displaying brownish hues.^[13] Low zircon, highly metamict and nearly amorphous, has significantly lowered properties (refractive index 1.78–1.81) and is typically green or brownish-green, though heat treatment can restore crystallinity and color in all types.^[13] Color varieties include hyacinth (orange-red, historical name), jacinth (brown), and metamict green forms, with blue achieved via heating; these arise from trace impurities like iron, uranium, or radiation effects.^[24]

Uses and Applications

Gemstone Varieties and Treatments

Zircon occurs in a wide array of colors that define its gemstone varieties, ranging from colorless to vibrant hues such as blue, yellow, orange, red, brown, green, and violet. The most popular variety is blue zircon, often with a greenish tint, which accounts for approximately 80% of market sales due to its vivid appeal and high dispersion that produces flashes of multicolored light. Colorless zircon is prized for its diamond-like brilliance and fire, while earth-toned varieties like cinnamon, sherry, yellow, orange, and reddish brown are also common in untreated rough. Red and green zircons are rarer and typically valued as collectors' items rather than mainstream jewelry stones.^[14] Gem zircons are further classified into high, intermediate, and low types based on the degree of radiation-induced metamictization, which affects their crystal structure and optical properties. High zircons exhibit minimal damage, resulting in clear, well-formed crystals with high refractive indices (1.92–1.98) and strong birefringence, making them ideal for faceting into brilliant cuts. Intermediate zircons show partial damage, with properties bridging the two extremes, while low zircons suffer extensive metamict alteration, often appearing cloudy or greenish and displaying lower refractive indices (around 1.81–1.85) and reduced birefringence. This classification influences their suitability as gems, with high types preferred for their superior clarity and sparkle.^[13] Cat's-eye zircon represents a distinctive variety formed when parallel inclusions create a chatoyant effect in cabochon cuts; this is exceedingly rare and typically occurs in brown or greenish material. Untreated zircons may exhibit smoky or cloudy appearances due to inclusions or radiation effects, historically used in mourning jewelry, but most modern gems are selected or treated for transparency.^[14] Heat treatment is the most common enhancement for zircon gems, routinely applied since the 1920s to improve color and repair radiation damage. Brownish rough, the predominant natural form, is heated in air at temperatures around 900–1,000°C to produce colorless or blue varieties, with the oxidizing atmosphere removing brown tones and stabilizing desirable hues. Heating in an oxygen-free environment yields golden yellow or orange colors, while reducing conditions can enhance reddish shades. This treatment recrystallizes metamict areas, enhancing clarity and durability, and is considered stable and undetectable in most cases, though some colors may fade under prolonged bright light exposure. Nearly all blue and colorless zircons in the market are heat-treated, as natural occurrences of these colors are exceptional.^[38]^[13]^[28] Other treatments are less common but include fracture filling with colorless oils or resins to improve apparent clarity in transparent zircons, similar to practices in other gems; this enhances durability but requires careful cleaning to avoid removal. Surface irradiation or coating is occasionally used but not standard for zircon. All enhancements must be disclosed in gem certifications to ensure transparency for buyers.^[38]

Industrial and Material Applications

Zircon, chemically ZrSiO₄, finds extensive use in industrial settings owing to its exceptional thermal stability, chemical inertness, and high melting point exceeding 2200°C. The principal applications encompass refractories, foundry sands, and ceramics, accounting for the majority of global zircon consumption, which totaled about 1.6 million metric tons in 2023.^[39] These uses leverage zircon's low thermal expansion and resistance to molten metals and slags, enabling it to withstand extreme conditions in manufacturing processes. In the foundry sector, zircon flour and sand are integral to investment casting and mold production, particularly for precision components in aerospace and automotive industries. The mineral's high refractoriness and fine particle size provide superior surface finish, minimal veining, and enhanced permeability, reducing defects in castings of metals like steel, aluminum, and titanium. Foundry applications consume approximately 14% of mined zircon, with its low bulk density further aiding in efficient mold collapse post-casting. Refractory materials incorporating zircon, such as zircon-mullite bricks and ramming mixes, protect furnace linings in steel, glass, and cement production. These products exhibit outstanding corrosion resistance to basic slags and fluxes, maintaining structural integrity at temperatures up to 1700°C. Zircon-based refractories are favored in electric arc furnaces and ladles, where they extend service life and reduce downtime, comprising a significant portion of the refractory market derived from zircon. Within ceramics, ground zircon acts as a primary opacifier and stabilizer in glazes, tiles, and sanitaryware, imparting opacity and whiteness by scattering light without coloring. It enhances durability and thermal shock resistance in porcelain and tableware, with about 54% of zircon production directed toward this sector. Additionally, zircon serves as a precursor for zirconia (ZrO₂) production, which is processed into advanced materials for oxygen sensors, fuel cells, and bioceramics in medical implants. Zircon-derived zirconium compounds are critical in the nuclear industry, where zirconium alloys clad fuel rods due to their low neutron absorption cross-section and corrosion resistance in reactor environments. These alloys, produced via processes like the Kroll method from zircon, ensure safe containment of fission products in light-water reactors. In chemical processing, zirconium chemicals from zircon provide linings for equipment handling aggressive acids and oxidizers, supporting applications in petrochemicals and pharmaceuticals.

Scientific and Dating Applications

Zircon (ZrSiO₄) is a key mineral in geochronology due to its ability to incorporate uranium (U) during crystallization while excluding lead (Pb), enabling precise U-Pb dating of geological events.^[8] This property allows zircons to record the age of igneous crystallization, metamorphic recrystallization, or sedimentation through detrital grains, providing insights into Earth's crustal evolution over billions of years.^[40] The U-Pb method in zircon is particularly robust because the mineral's chemical stability resists resetting of the isotopic clock during subsequent thermal events, making it ideal for dating ancient rocks.^[41] In detrital zircon geochronology, U-Pb ages from sedimentary rocks reveal provenance, maximum depositional ages, and basin evolution, with studies often analyzing 100–150 grains per sample for statistical reliability.^[42] High-precision techniques like CA-ID-TIMS (chemical abrasion-isotope dilution-thermal ionization mass spectrometry) achieve uncertainties as low as 0.02–0.1%, enabling resolution of short-duration magmatic events, such as those in lunar samples dated to 4.33 Ga.^[43]^[44] Global databases compiling millions of zircon U-Pb analyses have mapped continental growth and supercontinent cycles, demonstrating zircon's role in reconstructing 4.5 billion years of planetary history.^[40]^[45] Beyond dating, zircon serves as a recorder of magmatic conditions through trace element and isotopic analyses. Titanium concentrations in zircon enable thermometry, with the Ti-in-zircon geothermometer estimating crystallization temperatures from 500–850°C in granitic systems, calibrated against TiO₂ and SiO₂ activities.^[46]^[47] Oxygen isotope ratios (δ¹⁸O) in zircon trace magma sources, distinguishing mantle-derived from crustal melts, as low δ¹⁸O values indicate hydrothermal alteration influences.^[48] Hafnium isotopes (εHf) coupled with U-Pb dates reveal crustal reworking versus juvenile additions, informing models of tectonic settings like subduction zones.^[49] These multi-proxy approaches, often using in situ SIMS or LA-ICP-MS, provide integrated records of temperature, pressure, and composition during zircon formation.^[50]

Identification and Distinction

Diagnostic Properties

Zircon (ZrSiO₄) is readily identified in hand samples by its tetragonal prismatic crystal habit, often forming elongated, stubby, or bipyramidal crystals with a vitreous to adamantine luster.^[3] The mineral exhibits a hardness of 6.5–7.5 on the Mohs scale, with metamict varieties being softer, making it resistant to scratching by common tools but softer than corundum, and it displays a conchoidal fracture with indistinct cleavage on {110} and {111}.^[3] Its specific gravity ranges from 4.60 to 4.71, higher than most silicates due to the heavy zirconium content, which aids in separation during mineral processing.^[3] Optically, zircon is uniaxial positive with refractive indices of ω = 1.920(3) and ε = 1.984(3), yielding a birefringence of 0.059, which produces strong dispersion and fire in gem-quality specimens.^[3] Colors vary widely from colorless to brown, yellow, orange, red, or green, often with weak pleochroism in colored varieties,^[3] and it shows weak to moderate fluorescence under short-wave ultraviolet light, typically in yellow to orange hues.^[24] Radiation damage from incorporated uranium and thorium can alter these properties, lowering refractive index and specific gravity in metamict (low-type) zircon, a key diagnostic feature distinguishable by annealing tests that restore high-type characteristics.^[13] In thin section under polarized light microscopy, zircon appears as high-relief, colorless to pale grains with first-order white to yellow interference colors and parallel extinction, often with inclusions of apatite or monazite.^[3] Chemical tests confirm the presence of zirconium via spot tests or spectroscopy, while its resistance to acids except hydrofluoric distinguishes it from look-alikes.^[51]

Similar Minerals

Zircon can be visually confused with certain other minerals in gemological applications due to overlapping colors, high luster, and dispersion. Titanite, commonly known as sphene, is a frequent look-alike, particularly in its green to yellow varieties, where both minerals display strong fire and brilliance from high dispersion values (0.051 for titanite versus 0.039 for zircon). Distinction is achieved through titanite's softer hardness of 5–5.5 on the Mohs scale compared to zircon's 6.5–7.5, along with titanite's lower specific gravity (3.48–3.55 versus 4.60–4.71) and refractive index range (1.885–2.030 versus 1.810–1.985, often metamict-altered in zircon).^[52] Topaz, especially the blue variety produced by irradiation and heating, closely resembles heat-treated blue zircon in hue and transparency, making it a common substitute in jewelry. Topaz exhibits lower dispersion (0.014) and lacks zircon's pronounced double refraction (0.018–0.059 for zircon), while topaz is harder (Mohs 8) and has a refractive index of 1.610–1.638. Specific gravity also differs, with topaz at 3.49–3.57.^[53] Colorless zircon has long served as a natural simulant for diamond owing to its high refractive index and sparkle, though it is readily separated by diamond's exceptional hardness (Mohs 10), higher refractive index (2.42), and strong thermal conductivity, which zircon lacks.^[54] Structurally and chemically, zircon (ZrSiO₄) belongs to the zircon group of nesosilicates with a tetragonal crystal system, sharing isomorphism with hafnon (HfSiO₄), where hafnium substitutes zirconium such that Hf exceeds approximately 50 mol.% for classification as hafnon; the two are nearly indistinguishable in hand specimen and often coexist in granitic pegmatites.^[55]^[56] Xenotime (YPO₄) is a closely related orthophosphate mineral with an analogous structure, differing primarily in its phosphate composition and yttrium dominance, leading to a higher specific gravity (4.45–5.10) and frequent association with zircon in heavy mineral sands. Other group members include thorite (ThSiO₄) and coffinite (USiO₄), which incorporate thorium or uranium and exhibit metamictization similar to radiation-damaged zircon, but they are rarer and identified via elevated radioactivity or chemical analysis. These minerals play comparable roles in geochronology due to uranium-lead retention.^[57]

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Refractive index: birefringent 1.92-1.98 (high type). Max. Birefringence: 0.055 to 0.059 (high type). Dispersion: very high 0.039 (high type). Pleochroism ...<|control11|><|separator|>
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Zircon: The Metamorphic Mineral - GeoScienceWorld
Aug 1, 2017 · A mineral that forms under conditions as variable as diagenesis to deep subduction, melt crystallization to low temperature alteration.PREAMBLE: THE MANY... · PETROGRAPHY OF ZIRCON · MINERAL CHEMISTRY
[35]
(PDF) Zircon equilibria in metamorphic rocks - ResearchGate
It is demonstrated that solid-state zircon formation in metamorphic rocks is more likely to occur during retrograde rather than prograde processes. Zircon ...Abstract And Figures · References (149) · Recommended Publications
[36]
Zircon Care and Cleaning Guide - GIA
Treatment concerns Zircon is commonly heat-treated to produce blue and colorless varieties. As with any transparent gemstone, zircon can be fracture-filled to ...
[37]
A global zircon U–Th–Pb geochronological database
Nov 27, 2023 · We present a database of zircon U–Th–Pb geochronology that samples the global continental crust and spans nearly all of Earth's history.
[38]
[PDF] 4.10 U–Th–Pb Geochronology
For minerals where f<1, such as zircon and xenotime, the correction for 230Th disequilibrium has a lower limit at f¼0, yielding a date that is 110 ka too young ...
[39]
Use and abuse of detrital zircon U-Pb geochronology—A case from ...
Oct 9, 2018 · Geochronology-based studies of sediment provenance typically rely on dating n ≈ 100–150 single detrital zircon crystals from individual samples, ...
[40]
High-precision CA-ID-TIMS zircon U-Pb geochronology: a review of ...
Here we review recent advances in the CA-ID-TIMS zircon U-Pb dating method and discuss the factors that influence the choice of method used to date ...
[41]
High-precision U-Pb zircon dating identifies a major magmatic event ...
Jul 24, 2024 · Existing U-Pb dates of >500 zircons from several locations on the lunar nearside reveal a pronounced age peak at 4.33 billion years (Ga), suggesting a major, ...Materials And Methods · In Situ Zircon Trace Element... · Zircon Hf Isotopic Ratios
[42]
Enhanced U-Pb detrital zircon, Lu-Hf zircon, δ18O zircon, and Sm ...
Jan 9, 2024 · Six validated global isotopic databases provide extensive records of analyses from U-Pb in detrital zircon, Lu-Hf in zircon, Sm-Nd from whole rocks, and δ 18 O ...
[43]
Ti-in-zircon thermometry: applications and limitations
Feb 12, 2008 · Average apparent Ti-in-zircon temperatures range from 500° to 850°C, and are lower than either zircon saturation temperatures (for granitic rocks) or predicted ...
[44]
The Ti-in-zircon thermometer revised: The effect of pressure on the ...
Nov 1, 2023 · The Ti content of zircon (ZrSiO4) is strongly dependent on temperature and is widely used as a geothermometer (Watson et al., 2006, Ferry and ...
[45]
Oxygen Isotopes in Zircon | Reviews in Mineralogy and Geochemistry
Mar 3, 2017 · Isotopic and trace element analysis of zircons can provide reliable and robust estimates of age, compositions of coexisting minerals and ...
[46]
Regional zircon U-Pb geochronology for the Maniitsoq ... - Nature
May 25, 2021 · Zircon is by far the most commonly utilized mineral for U–Pb dating as it contains sufficient U for robust age determination, rejects common ...<|control11|><|separator|>
[47]
Considerations in Zircon Geochronology by SIMS - GeoScienceWorld
Mar 3, 2017 · Zircon is particularly suitable for SIMS U–Th–Pb geochronology. It is a physically and chemically robust mineral that crystallizes under a range of geological ...
[48]
[PDF] Zirconium and Hafnium - USGS Publications Warehouse
Jan 28, 2016 · Zircon (ZrSiO4 ) is the most common naturally occurring zirconium- and hafnium-bearing mineral. Most zircon forms as a product of primary ...
[49]
Sphene (Titanite) Value, Price, and Jewelry Information - IGS
Nov 10, 2024 · Because of its high dispersion and luster, colored cubic zirconia (CZ) can make a convincing sphene simulant. However, CZ lacks sphene's ...
[50]
December Birthstones: Blue Topaz, Blue Zircon, Tanzanite and ...
Apr 10, 2025 · Generally speaking, blue zircon is more expensive than blue topaz. Topaz is a naturally occurring mineral that comes in a variety of colors, but ...<|control11|><|separator|>
[51]
What Is Zircon Gemstone - GIA
Zircon is a colorful gem with high refraction and fire that's unfairly confused with cubic zirconia. Well known for its flashes of multicolored light.Missing: varieties | Show results with:varieties
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https://www.gemsociety.org/article/sphene-jewelry-and-gemstone-information/
[53]
Hafnon-Zircon Series: Mineral information, data and localities.
An isomorphous series between the end-members ZrSiO4-HfSiO4. If a (Hf,Zr)SiO4 sample has more than 90 mol-% Hafnium component it is classified as a hafnon.
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ALEX STREKEISEN-Xenotime-
The structure of xenotime is analogous to Zircon ... Xenotime is a very rare mineral, it is an accessory mineral in some alkaline granite, syenite and similar ...<|control11|><|separator|>