Molybdenite is a mineral of molybdenum disulfide, MoS2. Similar in appearance and feel to graphite, molybdenite has a lubricating effect that is a consequence of its layered structure. The atomic structure consists of a sheet of molybdenum atoms sandwiched between sheets of sulfur atoms. The Mo-S bonds are strong, but the interaction between the sulfur atoms at the top and bottom of separate sandwich-like tri-layers is weak, resulting in easy slippage as well as cleavage planes. Molybdenite crystallizes in the hexagonal crystal system as the common polytype 2H and also in the trigonal system as the 3R polytype.
Studtite, chemical formula [(UO2)O2(H2O)2]·2(H2O) or UO4·4(H2O), is a secondary uranium mineral containing peroxide formed by the alpha-radiolysis of water during formation. It occurs as pale yellow to white needle-like crystals often in acicular, white sprays.
Mosesite is a very rare mineral found in few locations. It is a mercury mineral found as an accessory in deposits of mercury, often in conjunction with limestone. It is known to be found in the U.S. states of Texas and Nevada, and the Mexican states of Guerrero and Querétaro. It was named after Professor Alfred J. Moses (1859–1920) for his contributions to the field of mineralogy in discovering several minerals found alongside mosesite. The mineral itself is various shades of yellow and a high occurrence of spinel twinning. It becomes isotropic when heated to 186 °C (367 °F).
Biehlite is an exceptionally rare mineral, an antimony arsenic bearing molybdate with formula [(Sb,As)O]2MoO4. It comes from Tsumeb.
Albrechtschraufite (IMA symbol: Asf) is a very rare complex hydrated calcium and magnesium-bearing uranyl fluoride carbonate mineral with formula Ca4Mg(UO2)2(CO3)6F2·17H2O. Its molar weight is 1,428.98 g, color yellow-green, streak white, density 2.6 g/cm3, Mohs hardness 2-3, and luster is vitreous (glassy). It is named after Albrecht Schrauf (1837–1897), Professor of Mineralogy, University of Vienna. Its type locality is Jáchymov, Jáchymov District, Krušné Hory Mountains, Karlovy Vary Region, Bohemia, Czech Republic.
Bergenite is a rare uranyl phosphate of the more specific phosphuranylite group. The phosphuranylite-type sheet in bergenite is a new isomer of the group, with the uranyl phosphate tetrahedra varying in an up-up-down, same-same-opposite (uuduudSSOSSO) orientation. All bergenite samples have been found in old mine dump sites. Uranyl minerals are a large constituent of uranium deposits.
Johannite is a rare uranium sulfate mineral. It crystallizes in the triclinic crystal system with the chemical composition Cu[UO2(OH)SO4]2·8H2O. It crystallizes in the triclinic system and develops only small prism or thin to thick tabular crystals, usually occurs as flaky or spheroidal aggregates and efflorescent coatings. Its color is emerald-green to apple-green and its streak is pale green.
Rameauite is a hydrated complex uranyl oxide mineral with formula K2Ca(UO2)6OH16·H2O or K2CaU6+6O20·9H2O.
In chemistry, a molybdate is a compound containing an oxyanion with molybdenum in its highest oxidation state of 6: O−−Mo(=O)2−O−. Molybdenum can form a very large range of such oxyanions, which can be discrete structures or polymeric extended structures, although the latter are only found in the solid state. The larger oxyanions are members of group of compounds termed polyoxometalates, and because they contain only one type of metal atom are often called isopolymetalates. The discrete molybdenum oxyanions range in size from the simplest MoO2−
4, found in potassium molybdate up to extremely large structures found in isopoly-molybdenum blues that contain for example 154 Mo atoms. The behaviour of molybdenum is different from the other elements in group 6. Chromium only forms the chromates, CrO2−
4, Cr
2O2−
7, Cr
3O2−
10 and Cr
4O2−
13 ions which are all based on tetrahedral chromium. Tungsten is similar to molybdenum and forms many tungstates containing 6 coordinate tungsten.
Derriksite is a very rare uranium mineral with the chemical formula Cu4(UO2)(SeO3)2(OH)6•H2O. It is a secondary mineral that contains copper, uranium and the rarer selenium. It is a bright green to duller bottle green colour. Its crystal habit is acicular, it is most likely to be found along with the uranyl selenium mineral demesmaekerite, but derriksite is much rarer than demesmaekerite. It is named after Jean Marie Francois Joseph Derriks (1912–1992), geologist and administrator of the Union Minière du Haut Katanga (UMHK). It has a Mohs hardness of about 2.
Ferrimolybdite is a hydrous iron molybdate mineral with formula: Fe3+2(MoO4)3·8(H2O) or Fe3+2(MoO4)3·n(H2O). It forms coatings and radial aggregates of soft yellow needles which crystallize in the orthorhombic system.
Lindgrenite is an uncommon copper molybdate mineral with formula: Cu3(MoO4)2(OH)2. It occurs as tabular to platey monoclinic green to yellow green crystals.
Ichnusaite (pronounced iknusa-ait) is a very rarely found mineral. Ichnusaite is a natural compound of thorium and molybdenum with the formula Th(MoO4)2·3H2O. It was discovered in Su Seinargiu, Sarroch, Cagliari, Sardegna, Italy in 2013. The name is from the old Greek name of Sardinia, Ιχνουσσα, Ichnusa.
This locality is also a place of discovery of the second natural thorium molybdate - nuragheite.
Tancaite-(Ce) is a very rare molybdate mineral with the formula FeCe(MoO4)3•3H2O. It was found in Punta de Su Seinargiu locality on Sardinia, Italy. Red crystals of tancaite-(Ce) resemble modified cubes, but the mineral is trigonal (space group R-3). The type locality of tancaite-(Ce) is also a place of discovery of other molybdate minerals, including thorium molybdates ichnusaite and nuragheite.
Nuragheite is a rare natural thorium molybdate, formula Th(MoO4)2·H2O, discovered in Su Seinargiu, Sarroch, Cagliari, Sardegna, Italy. This locality is also a place of discovery of the other thorium molybdate - ichnusaite, which is a trihydrate.
Peggy-Kay Hamilton (1922–1959) was born in Illinois in 1922 and was an American Research Associate in Mineralogy in the Department of Geology at Columbia University. One of Hamilton's first research breakthroughs was developing Research Project 49, otherwise known as the study of clay minerals. In her later research years, her focus shifted and led to her becoming involved full time in the study of uranium.
Bieberite (CoSO4 · 7H2O) is a pinkish red colored sulfate mineral high in cobalt content. The name is derived from the type locality at the copper deposit in Bieber, Hesse, Germany. It has been described and reported as far back as the 1700s. Bieberite primarily occurs as a secondary mineral, forming in cobalt-bearing arsenide and sulfide deposits through oxidation.
Sengierite is a rare oxide and hydroxide mineral, chemically a copper and uranyl vanadate, belonging to the carnotite group. Its chemical formula is Cu2(OH)2[UO2|VO4]2·6H2O.
Arsenuranospathite (IMA symbol: Aush) is a rare mineral with the chemical formula Al(UO2)2(AsO4)2F·20H2O. The name "arsenuranospathite" as arsenate analog of uranospathite was first used by Walenta (1963) with reference to a uranyl-arsenate mineral from Black Forest (Schwarzwald) massif, Germany.
Meyrowitzite, Ca(UO2)(CO3)2·5H2O, is a carbonate mineral verified in May of 2018 by the Commission of New Minerals, Nomenclature and Classification of the International Mineralogical Association. It is an extremely rare mineral, discovered in the Markey mine Utah, U.S.A. The mineral is a transparent yellow and has blades up to approximately 0.2 mm in length. It is soluble in water or aqueous solutions. Meyrowitzite is named in honor of Robert Meyrowitz (1916-2013), an American analytical chemist. After serving in WW II, he joined the United States Geological Survey (USGS). He was known for developing innovative new methods for analyzing small and difficult to study mineralogical samples along with his formulation of the high-index immersion liquids.
Radioactive