Also found in: Dictionary, Thesaurus, Wikipedia.


a reddish-brown, grey, green, blue, or colourless hard mineral consisting of zirconium silicate in tetragonal crystalline form with hafnium and some rare earths as impurities. It occurs principally in igneous rocks and is an important source of zirconium, zirconia, and hafnia: it is used as a gemstone and a refractory. Formula: ZrSiO4



(from the German Zirkon; original source, Persian zargun, “golden”), a mineral, a nesosilicate with the composition Zr[SiO4]. Distinctions are made between zircons on the basis of impurity content: alvite contains hafnium and thorium, oyamalite contains transition metals and phosphorus, hagathalite contains transition metals and niobium, and naegite contains transition metals, thorium, niobium, and tantalum. Metamict dipyramidal zircons containing thorium, uranium, and water (Th > U) are called malacons, while prismatic zircons (Th < U) are called cyrtolites. Honey yellow, red-brown, and pink transparent zircons are called hyacinths. Metacolloidal, collomorphic zircons are called arshinovites.

Zircon crystallizes in the tetragonal system, forming tabular, short prismatic, or, less often, dipyramidal crystals. Regular concretions with xenotime, YPO4, are frequent. Zircons are brownish yellow to brown, grayish, red, or pink; they may sometimes be colorless. Zircons are transparent to translucent. They usually exhibit no cleavage. Zircons have a hardness of 7–8 on Mohs’ scale and a density of 4,680–4,710 kg/m3 (in the metamict varieties, the hardness and density are less).

Zircon is a characteristic accessory mineral in granites and nepheline syenites and their effusive analogues, as well as of various metamorphic and terrigenous sedimentary rocks; large zircon deposits are found in granitic and alkaline pegmatites. Zircon sometimes concentrates in industrial quantities together with pyrochlore in zones of albitization of alkali rocks. Upon weathering of rocks containing zircon, the mineral may form alluvial deposits. Large reserves of zircon are found in the littoral-marine deposits on the Atlantic coast of the USA (Florida), on the island of Sri Lanka, and in eastern Australia.

Zircon is the major source for the production of zirconium, hafnium, and zirconium oxide (zirconium dioxide). Pure zircon sands are used in mold casting, as well as a starting material in the production of refractories and special ceramic materials. Hyacinth and transparent yellow and green zircons are used in jewelry-making (class II gems).



ZrSiO4 A brown, green, pale-blue, red, orange, golden-yellow, grayish, or colorless neosilicate mineral occurring in tetragonal prisms; it is the chief source of zirconium; the colorless varieties provide brilliant gemstones. Also known as hyacinth; jacinth; zirconite.
References in periodicals archive ?
The minerals comprising the dykes include K-feldspar (microperthite), quartz, riebekite, biotite, muscovite, epidote, titanite, kaolin, apatite, zircon and limonite.
This enhancement sits alongside Iluka's existing position as the largest global zircon producer.
Russia's nuclear-powered missile cruisers Admiral Nakhimov and Pyotr Veliky will be installed with the Zircon missiles, another source told Tass.
Aluminium based Hybrid Metal Matrix composites containing Zircon and [Al.
Microscopic observation of the asteriated zircon revealed three sets of oriented planar features (Figure 29, left), each perpendicular to the weaker branches of the star, combined with a set of very fine short tubes or fissures that were responsible for the distinctly more intense branch (vertical in Figure 28).
Zircon crystals, which are very resistant to heat and corrosion, are ubiquitous in the crust of Earth.
The combination of 74% fused silica, 24% zircon, 2% alumina shows excellent stability at high temperatures and can be used in a wide range of core sizes and designs.
Other batholiths of this southern part of the CIZ have been dated by U-Pb zircon geochronology (Castelo Branco: Antunes et al.
It is worth testing whether this putative change in regional basin geometry could be indeed reflected in the detrital zircon population from Paleozoic sandstones of the mid-Baltic area.
Moser's unique facility, the Zircon and Accessory Phase Laboratory (ZAPLab), hosts a sophisticated electron microscopy array designed specifically to examine these rugged crystals.
First samples were taken, then thin layers were made of the samples that led to the discovery of accessory minerals like zircon, sphene and apatite.