Sylvanite or silver gold telluride, chemical formula (Ag,Au)Te2, is the most common telluride of gold.
Tellurite is a rare oxide mineral composed of tellurium dioxide (TeO2).
Sugilite ( SOO-gə-lyte, -jee-) is a relatively rare pink to purple cyclosilicate mineral with the complex chemical formula KNa2(Fe, Mn, Al)2Li3Si12O30. Sugilite crystallizes in the hexagonal system with prismatic crystals. The crystals are rarely found and the form is usually massive. It has a Mohs hardness of 5.5–6.5 and a specific gravity of 2.75–2.80. It is mostly translucent. Sugilite was first described in 1944 by the Japanese petrologist Ken-ichi Sugi (1901–1948) for an occurrence on Iwagi Islet, Japan, where it is found in an aegirine syenite intrusive stock. It is found in a similar environment at Mont Saint-Hilaire, Quebec, Canada. In the Wessels mine in Northern Cape Province of South Africa, sugilite is mined from a strata-bound manganese deposit. It is also reported from Liguria and Tuscany, Italy; New South Wales, Australia and Madhya Pradesh, India.
Tellurobismuthite, or tellurbismuth, is a telluride mineral: bismuth telluride (Bi2Te3). It crystallizes in the trigonal system. There are natural cleavage planes in the (0001) direction as the crystal is effectively lamellar (layered) in that plane. The Mohs hardness is 1.5 - 2 and the specific gravity is 7.815. It is a dull grey color, which exhibits a splendent luster on fresh cleavage planes.
Cesbronite is a copper-tellurium oxysalt mineral with the chemical formula Cu3Te6+O4(OH)4 (IMA 17-C). It is colored green and its crystals are orthorhombic dipyramidal. Cesbronite is rated 3 on the Mohs Scale. It is named after Fabien Cesbron (born 1938), a French mineralogist.
Clinohedrite is a rare silicate mineral. Its chemical composition is a hydrous calcium-zinc silicate; CaZn(SiO4)·H2O. It crystallizes in the monoclinic system and typically occurs as veinlets and fracture coatings. It is commonly colorless, white to pale amethyst in color. It has perfect cleavage and the crystalline habit has a brilliant luster. It has a Mohs hardness of 5.5 and a specific gravity of 3.28–3.33.
Alabandite or alabandine is a rarely occurring manganese sulfide mineral. It crystallizes in the cubic crystal system with the chemical composition Mn2+S and develops commonly massive to granular aggregates, but rarely also cubic or octahedral crystals to 1 cm.
Zemannite is a very rare oxide mineral with the chemical formula Mg0.5ZnFe3+[TeO3]3·4.5H2O. It crystallizes in the hexagonal crystal system and forms small prismatic brown crystals. Because of the rarity and small crystal size, zemannite has no applications and serves as a collector's item.
Walfordite is a very rare tellurite mineral that was discovered in Chile in 1999. The mineral is described as orange with orange-yellow streak, and is determined to have a chemical formula of Fe3+,Te6+Te4+3O8 with minor titanium and magnesium substitution resulting in an approximate empirical formula of (Fe3+,Te6+,Ti4+,Mg)(Te4+)3O8.
Emmonsite, also known as durdenite, is an iron tellurite mineral with the formula: Fe2(TeO3)3·2(H2O). Emmonsite forms triclinic crystals. It is of a yellowish-green color, with a vitreous luster, and a hardness of 5 on the Moh scale.
Kanoite is a light pinkish brown silicate mineral that is found in metamorphic rocks. It is an inosilicate and has a chemical formula of (Mg,Mn2+)2Si2O6. It is a member of pyroxene group and clinopyroxene subgroup.
Rodalquilarite is a rare iron tellurite chloride mineral with formula H3Fe3+2(Te4+O3)4Cl or Fe2(TeO2OH)3(TeO3)Cl. Rodalquilarite crystallizes in the triclinic system and typically occurs as stout green prisms and encrustations.
Tlapallite is a rare and complex tellurate mineral with the chemical formula (Ca,Pb)3CaCu6[Te4+3Te6+O12]2(Te4+O3)2(SO4)2·3H2O. It has a Moh's hardness of 3 and it is green in colour. It was named after the Nahua word "Tlalpalli", which translates to paint, referring to the paint-like habit of the mineral. Its formula and crystal structure were redefined in 2019, showing it contained a mixed-valence phyllotellurate layer [Te4+3Te6+O12]12−.
Carlfriesite is a rare tellurium mineral with the formula CaTe4+2Te6+O8, or more simplified: CaTe3O8. It has a Moh's hardness of 3.5 and it occurs in various shades of yellow, ranging from bright yellow to a light buttery color. It was named after Carl Fries Jr. (1910–1965) from the U.S. Geological Survey and the Geological Institute of the National University, Mexico City, Mexico. It was previously thought to have the formula H4Ca(TeO3)3, but this was proven to be incorrect. It has no uses beyond being a collector's item.
Tlalocite is a rare and complex tellurate mineral with the formula Cu10Zn6(TeO4)2(TeO3)(OH)25Cl · 27 H2O. It has a Mohs hardness of 1, and a cyan color. It was named after Tlaloc, the Aztec god of rain, in allusion to the high amount of water contained within the crystal structure. It is not to be confused with quetzalcoatlite, which often looks similar in color and habit.
Quetzalcoatlite is a rare tellurium oxysalt mineral with the formula Zn6Cu3(TeO6)2(OH)6 · AgxPbyClx+2y. It also contains large amounts of silver- and lead(II)chloride with the formula AgxPbyClx+2y (x+y≤2). It has a Mohs hardness of 3 and it crystallizes in the trigonal system. It has a deep blue color. It was named after Quetzalcoatl, the Aztec and Toltec god of the sea, alluding to its color. It is not to be confused with tlalocite, which has a similar color and habit.
Trogtalite is a rare selenide mineral with the formula CoSe2. It crystallizes in the cubic system and is part of the pyrite group, consisting of Co2+ and Se22− ions. It has a rose-violet colour and its crystals are opaque. It often occurs as grains. It was thought to be dimorphous with hastite, but this was discredited in 2009. Hastite turned out to be the iron selenide mineral ferroselite. It forms a solid solution series with kruťaite.
Berzelianite is a rare copper selenide mineral with the formula Cu2Se. It occurs as thin dendritic crusts or as fine-grained inclusions. It crystallizes in the isometric system, unlike its dimorph, bellidoite, which crystallizes in the tetragonal system. The crystals are opaque and slightly malleable.
Khinite is a rare tellurate mineral with the formula Pb2+Cu2+3TeO6(OH)2. It crystallizes in the orthorhombic system and has a bottle-green colour. It is often found as dipyramidal, curved or corroded crystals no more than 0.15 mm in size. The tetragonal dimorph of khinite is called parakhinite.
Northstarite is an immensely rare lead-tellurite-thiosulfate mineral with an ideal formula of Pb6(Te4+ O3)5(S6+O3S2-). Northstarite was first discovered in 2019 by Charles Adan in the North Star Mine of the Tintic Mining District, Juab County, Utah, USA. Northstarite received its name after this type locality where it was originally discovered, the North Star Mine. Northstarite is the fourth thiosulfate mineral that exists on Earth, and although all thiosulfates have essential lead components, northstarite is the first thiosulfate species containing groups of both thiosulfate and tellurite (Te4+O3).
