Zircon is a mineral belonging to the group of nesosilicates. Its chemical name is zirconium silicate and its corresponding chemical formula is ZrSiO₄. Hafnium is almost always present in quantities ranging from 1 to 4%. The crystal structure of zircon is tetragonal crystal class. The natural color of zircon varies between colorless, yellow-golden, red, brown, and green. Colorless specimens that show gem quality are a popular substitute for diamond; these specimens are also known as "Matura diamond" (but note that cubic zirconia is a completely different synthetic substance with a different chemical composition). Image File history File links Zircão. ... Minerals are natural compounds formed through geological processes. ... A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... General Name, Symbol, Number zirconium, Zr, 40 Chemical series transition metals Group, Period, Block 4, 5, d Appearance silvery white Atomic mass 91. ... In chemistry, a silicate is a compound containing an anion in which one or more central silicon atoms are surrounded by electronegative ligands. ... In mineralogy, shape and size give rise to descriptive terms applied to the typical appearance, or habit of crystals. ... In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... In crystallography, the tetragonal crystal system is one of the 7 lattice point groups. ... Cleavage, in mineralogy, is the tendency of crystalline materials to split along definite planes, creating smooth surfaces, of which there are several named types: Basal cleavage: cleavage parallel to the base of a crystal, or to the plane of the lateral axes. ... For fractures in geologic formations, see Rock fracture. ... Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer. ... Lustre (American English: luster) is a description of the way light interacts with the surface of a crystal, rock or mineral. ... The refractive index (or index of refraction) of a material is the factor by which the phase velocity of electromagnetic radiation is slowed in that material, relative to its velocity in a vacuum. ... A calcite crystal laid upon a paper with some letters showing the double refraction Birefringence, or double refraction, is the decomposition of a ray of light into two rays (the ordinary ray and the extraordinary ray) when it passes through certain types of material, such as calcite crystals, depending on... Minerals are natural compounds formed through geological processes. ... Relative density (also known as specific gravity) is a measure of the density of a material. ... Fusibility is the ease with which a material will melt. ... Solubility refers to the ability for a given substance, the solute, to dissolve in a solvent. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ... Radioactivity may mean: Look up radioactivity in Wiktionary, the free dictionary. ... Minerals are natural compounds formed through geological processes. ... The silicate minerals make up the largest and most important class of rock-forming minerals. ... General Name, Symbol, Number zirconium, Zr, 40 Chemical series transition metals Group, Period, Block 4, 5, d Appearance silvery white Atomic mass 91. ... In chemistry, a silicate is a compound containing an anion in which one or more central silicon atoms are surrounded by electronegative ligands. ... General Name, Symbol, Number zirconium, Zr, 40 Chemical series transition metals Group, Period, Block 4, 5, d Appearance silvery white Atomic mass 91. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance as coarse powder, dark gray with bluish tinge Atomic mass 28. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ... General Name, Symbol, Number hafnium, Hf, 72 Chemical series transition metals Group, Period, Block 4, 6, d Appearance gray steel Atomic mass 178. ... In crystallography, the tetragonal crystal system is one of the 7 lattice point groups. ... In crystallography, a crystallographic point group or crystal class is a set of symmetry operations that leave a point fixed, like rotations or reflections, which leave the crystal unchanged. ... This article is about the gemstone. ... A round brilliant-cut cubic zirconia Cubic zirconia (or CZ) is zirconium oxide (ZrO2), a mineral that is extremely rare in nature but is widely synthesized for use as a diamond simulant. ...

The name derives from the Arabic word zarqun, meaning vermilion, or perhaps from the Persian zargun, meaning golden-colored. These words are corrupted into "jargoon", a term applied to light-colored zircons. Yellow zircon is called hyacinth, from a word of East Indian origin; in the Middle Ages all yellow stones of East Indian origin were called hyacinth, but today this term is restricted to the yellow zircons. Arabic ( or just ) is the largest living member of the Semitic language family in terms of speakers. ... Vermilion, also spelled vermillion, when found naturally-occurring, is an opaque reddish orange pigment, used since antiquity, originally derived from the powdered mineral cinnabar. ... Persian (Local names: فارسی Fârsi or پارسی Pârsi)* is an Indo-European language spoken in Iran, Afghanistan and Tajikistan as well as by minorities in Uzbekistan, Turkmenistan, India, Pakistan, Azerbaijan, Armenia, Georgia, Southern Russia, neighboring countries, and elsewhere. ...

Zircon is regarded as the traditional birthstone for December. A birthstone is a gemstone or other semi-precious stone which is associated with a month of the Gregorian Calendar. ...

Properties

Optical microscope photograph; the length of the crystal is about 250 µm.

Zircon is a remarkable mineral, if only for its almost ubiquitous presence in the crust of Earth. It is found in igneous rocks (as primary crystallization products), in metamorphic rocks and in sedimentary rocks (as detrital grains). Large zircon crystals are seldom abundant. Their average size, e.g. in granite rocks, is about 100–300 µm, but they can also grow to sizes of several centimeters, especially in pegmatites. a light-optical picture of a zircon File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... a light-optical picture of a zircon File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... A micrometre (American spelling: micrometer, symbol µm) is an SI unit of length. ... Earth cutaway from core to exosphere. ... Volcanic rock on North America Plutonic rock on North America Igneous rocks are formed when rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. ... Quartzite, a form of metamorphic rock, from the Museum of Geology at University of Tartu collection. ... This article or section does not adequately cite its references or sources. ... Granite is a common and widely-occurring group of intrusive felsic igneous rocks that form at great depths and pressures under continents. ... This article or section does not cite its references or sources. ...

Owing to their uranium and thorium content, some zircons may undergo metamictization. This partially disrupts the crystal structure and explains the highly variable properties of zircon. General Name, Symbol, Number uranium, U, 92 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Atomic mass 238. ... General Name, Symbol, Number thorium, Th, 90 Chemical series Actinides Group, Period, Block n/a, 7, f Appearance silvery white Atomic mass 232. ... Metamictization (sometimes called metamiction) is a natural process resulting in the gradual and ultimately complete destruction of a minerals crystal lattice, leaving the mineral amorphous. ...

Zircon is a common accessory mineral and found worldwide. Noted occurrences include: in the Ural Mountains; Trentino, Monte Somma; and Vesuvius, Italy; Arendal, Norway; Sri Lanka, India; Thailand; Ratanakiri, Cambodia; at the Kimberley mines, Republic of South Africa; Madagascar; and in Canada in Renfrew County, Ontario, and Grenville, Quebec. In the United States: Litchfield, Maine; Chesterfield, Massachusetts; in Essex, Orange, and St. Lawrence Counties, New York; Henderson County, North Carolina; the Pikes Peak district of Colorado; and Llano County, Texas. Map of the Ural Mountains The Ural Mountains (Russian: , Uralskiye gory) (also known as the Urals, the Riphean Mountains in Greco-Roman antiquity, and known as the Stone Belt) are a mountain range that runs roughly north and south through western Russia. ... Mount Vesuvius (Italian: Monte Vesuvio) is a volcano east of Naples, Italy, located at 40°49′N 14°26′ E. It is the only active volcano on the European mainland, although it is not currently erupting. ... Ratanakiri is a province in the northeast of Cambodia. ... Motto: Ut Incepit Fidelis Sic Permanet (Latin: Loyal she began, loyal she remains) Official languages English (de facto) Capital Toronto Largest city Toronto Lieutenant-Governor James K. Bartleman Premier Dalton McGuinty (Liberal) Parliamentary representation  - House seats  - Senate seats 106 24 Area Total  - Land  - Water  (% of total)  Ranked 4th 1,076... Litchfield is a town located in Kennebec County, Maine. ... Chesterfield is a town located in Hampshire County, Massachusetts. ... NY redirects here. ... Location in the state of North Carolina Formed 1838 Seat Hendersonville Area  - Total  - Water 971 km² (375 mi²) 3 km² (1 mi²) 0. ... Pikes Peak (formerly Pikes Peak, see below) is a mountain in the Front Range of the Rocky Mountains, 10 miles (16 km) west of Colorado Springs, Colorado, in El Paso County. ... Official language(s) English Capital Denver Largest city Denver Area  Ranked 8th  - Total 104,185 sq mi (269,837 km²)  - Width 280 miles (451 km)  - Length 380 miles (612 km)  - % water 0. ... Llano County (pronounced ) is a county located in the state of Texas. ...

Thorite (ThSiO₄) is an isostructural related mineral. Thorite, (Th,U)SiO4, is a rare nesosilicate of thorium that crystallizes in the tetragonal system and is isomorphous with zircon. ...

Zircon can come in red, brown, yellow, green, black, or colorless

Uses

Zircon dust

Commercially, zircons are mined for the metal zirconium which is used for abrasive and insulating purposes. It is the source of zirconium oxide, one of the most refractory materials known. Crucibles of ZrO are used to fuse platinum at temperatures in excess of 1755 ^oC. Zirconium metal is used in nuclear reactors due to its neutron absorption properties. Large specimens are appreciated as gemstones, owing to their high refractive index (zircon has a refractive index of around 1.95, diamond around 2.4). The color of zircons that do not have gem quality can be changed by heat treatment. Depending on the amount of heat applied, colorless, blue and golden-yellow zircons can be made. Zircon is also used as a protective coating on tweezers. Zircon dust. ... Zircon dust. ... Zirconia (ZrO2) is a white crystalline oxide of zirconium that is used as a refractory, in insulation, abrasives, enamels and glazes. ... The term refractory can refer to multiple things: A refractory clergyman is one who refused to swear an oath to the French Revolution-era French state under the Civil Constitution of the Clergy. ... General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Atomic mass 195. ... Nuclear power station at Leibstadt, Switzerland. ... ≈≈ This article or section does not cite its references or sources. ... A selection of gemstone pebbles made by tumbling rough rock with abrasive grit, in a rotating drum. ... The refractive index (or index of refraction) of a material is the factor by which the phase velocity of electromagnetic radiation is slowed in that material, relative to its velocity in a vacuum. ... This article is about the gemstone. ...

Zircons and the age of Earth

A piece of zircon estimated to be the oldest object on Earth

The pervasive occurrence of zircon has become more important since the discovery of radiometric dating. Zircons contain amounts of uranium and thorium (from 10 ppm up to 1 wt%) and can be dated using modern analytical techniques. Since zircons have the capability to survive geologic processes like erosion, transport, even high-grade metamorphism, they are used as protolith indicators. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... The oldest known object on Earth is a tiny speck of zircon crystal. ... Radiometric dating is a technique used to date materials based on a knowledge of the decay rates of naturally occurring isotopes, and the current abundances. ... General Name, Symbol, Number uranium, U, 92 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Atomic mass 238. ... General Name, Symbol, Number thorium, Th, 90 Chemical series Actinides Group, Period, Block n/a, 7, f Appearance silvery white Atomic mass 232. ... Parts per million (ppm) is a measure of concentration that is used where low levels of concentration are significant. ... Severe soil erosion in a wheat field near Washington State University, USA. For erosion as understood by materials science, see Erosion (materials science) For erosion as an English analogy, see Erosion (figurative) For erosion as an operation of Mathematical morphology, see Erosion (morphology) Erosion is the displacement of solids (soil... Metamorphism can be defined as the mineralogical, chemical and crystallographic changes in a solid-state rock, i. ...

The oldest minerals found so far are zircons from Jack Hills in the Narryer Gneiss Terrane, Yilgarn Craton, Western Australia, with an age of 4.404 billion years 1. This age is interpreted to be the age of crystallization. These zircons might not only be the oldest minerals on earth, they also show another interesting feature. Their oxygen isotopic composition has been interpreted to indicate that more than 4.4 billion years ago there was already water on the surface of the Earth. This is a spectacular interpretation that has been published in top scientific journals but is currently the subject of debate. It may be that the oxygen isotopes, and other compositional features (the rare earth elements), record more recent hydrothermal alteration of the zircons rather than the composition of the magma at the time of their original crystallization. The oldest rock or rocks on Earth are from the Archean Eon and are only partially exposed on the surface. ... Location of the Jack Hills in Australia The Jack Hills are located in the Narryer Gneiss Terrane of the Yilgarn Craton, Western Australia, and comprise an 80 km long northeast-trending belt of folded and metamorphosed supracrustal rocks. ... The Narryer Gneiss Terrane complex is verifiably the oldest known portion of the crust on Earth. ... // The Yilgarn Craton is a huge craton which constitutes the bulk of the Western Australian land mass. ... Capital Perth Government Constitutional monarchy Governor Ken Michael Premier Alan Carpenter (ALP) Federal representation  - House seats 15  - Senate seats 12 Gross State Product (2004-05)  - Product ($m)  $100,900 (4th)  - Product per capita  $50,355/person (3rd) Population (December 2006)  - Population  2,050,900 (4th)  - Density  0. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ... Isotopes are any of the several different forms of an element each having different atomic mass. ... Rare earth ore Rare earth elements and rare earth metals are trivial names sometimes applied to a collection of 17 chemical elements in the periodic table, namely scandium, yttrium, and the lanthanides. ... Hydrothermal circulation in the oceans is the passage of the water through mid-ocean Ridge (MOR) systems. ...

See also

• list of minerals
• History of Earth
• Radiometric dating

Gem animals. ... The planet Earth, photographed in the year 1972. ... Radiometric dating is a technique used to date materials based on a knowledge of the decay rates of naturally occurring isotopes, and the current abundances. ...

Further reading

The structure of zircon has a space group I41/amd

• The most comprehensive and up-to-date work on zircon and its related disciplines is the Mineralogical Society of America monograph published in late 2003: Hanchar & Hoskin (2003). Zircon. Reviews in Mineralogy and Geochemistry, volume 53, 500 pages. http://www.minsocam.org/MSA/RIM/Rim53.html
• D. J. Cherniak and E. B. Watson (2000). "Pb diffusion in zircon". Chemical Geology 172: pp. 5-24. 
• A. N. Halliday (2001). "In the beginning…". Nature 409: pp. 144-145. 
• Hermann Köhler (1970). "Die Änderung der Zirkonmorphologie mit dem Differentiationsgrad eines Granits". Neues Jahrbuch Mineralogische Monatshefte 9: pp. 405 - 420. 
• K. Mezger and E. J. Krogstad (1997). "Interpretation of discordant U-Pb zircon ages: An evaluation". Journal of Metamorphic Geology 15: pp. 127-140. 
• J. P. Pupin (1980). "Zircon and Granite petrology". Contributions to Mineralogy and Petrology 73: pp. 207-220. 
• Gunnar Ries (2001). "Zirkon als akzessorisches Mineral". Aufschluss 52: pp. 381-383. 
• P. Tondar (1991): Zirkonmorphologie als Charakteristikum eines Gesteins. Dissertation an der Ludwig-Maximilians-Universität München, 87 pp.
• G. Vavra (1990). "On the kinematics of zircon growth and its petrogenetic significance: a cathodoluminescence study". Contributions to Mineralogy and Petrology 106: pp. 90-99. 
• G. Vavra (1994). "Systematics of internal zircon morphology in major Variscan granitoid types". Contributions to Mineralogy and Petrology 117: pp. 331-344. 
• John W. Valley, William H. Peck, Elizabeth M. King, Simon A. Wilde (2002). "A Cool Early Earth". Geology 30: 351-354. DOI:10.1130/0091-7613(2002)030<0351:ACEE>2.0.CO;2 10.1130/0091-7613(2002)030<0351:ACEE>2.0.CO;2.  A Cool Early Earth. Zircons Are Forever. Retrieved on 11 April, 2005.

Image File history File links Created by Me, an elusive member, using the tools at http://cst-www. ... Image File history File links Created by Me, an elusive member, using the tools at http://cst-www. ... The space group of a crystal is a mathematical description of the symmetry inherent in the structure. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ...

References

• Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., ISBN 0-471-80580-7
• Geochemistry of old zircons
• Mineral galleries
• Webmineral
• Mindat

External links

• Links to external chemical sources