Minerals in space group 166

Antimony is a chemical element with the symbol Sb () and atomic number 51. A lustrous grey metal or metalloid, it occurs in nature mainly in the form of the sulfide mineral stibnite (). Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name kohl.

Bismuth is a chemical element; it has symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs naturally, and its sulfide and oxide forms are important commercial ores. The free element is 86% as dense as lead. It is a brittle metal with a silvery-white color when freshly produced. Surface oxidation generally gives samples of the metal a somewhat rosy cast. Further oxidation under heat can give bismuth a vividly iridescent appearance due to thin-film

Alunite is a hydroxylated aluminium potassium sulfate mineral, formula KAl3(SO4)2(OH)6. It was first observed in the 15th century at Tolfa, near Rome, where it was mined for the manufacture of alum. First called aluminilite by J.C. Delamétherie in 1797, this name was contracted by François Beudant three decades later to alunite. left|thumb|Alunite from Slovakia Alunite crystals morphologically are rhombohedra with interfacial angles of 90° 50', causing them to resemble cubes. Crystal symmetry is trigonal. Minute glistening crystals have also been found loose in cavities in altered rhyolite. Al

Jarosite is a basic hydrous sulfate of potassium and ferric iron (Fe-III) with a chemical formula of KFe3(SO4)2(OH)6. This sulfate mineral is formed in ore deposits by the oxidation of iron sulfides. Jarosite is often produced as a byproduct during the purification and refining of zinc and is also commonly associated with acid mine drainage and acid sulfate soil environments.

Chabazite () is a tectosilicate mineral series in the zeolite group, closely related to gmelinite, with the chemical formula , where M is one or more metal cations. Recognized minerals in the series include Chabazite-Ca, Chabazite-K, Chabazite-Na, and Chabazite-Sr, depending on the prominence of the indicated cation.

thumb|Pink eudialyte in syenite ([[lujavrite) from Poços de Caldas, Brazil. The white mineral is alkali feldspar, the black is aegirine, and the little brown bits are biotite.]]

Beudandite is a secondary mineral occurring in the oxidized zones of polymetallic deposits. It is a lead, iron, arsenate, sulfate with endmember formula: PbFe3(OH)6SO4AsO4.

Hydrotalcite, or formerly also völknerite, is a layered double hydroxide (LDH) of general formula , whose name is derived from its resemblance with talc and its high water content. Multiple structures containing loosely bound carbonate () ions exist. The easily exchangeable carbonates enable applications of the mineral in wastewater treatment and the immobilisation of radioactive waste after nuclear fuel reprocessing.

Tetradymite is a mineral consisting of bismuth, tellurium and sulfide, Bi2Te2S, also known as telluric bismuth. If sulfur is absent the mineral is tellurobismuthite and the formula is then Bi2Te3. Traces of selenium are usually present. left|thumb|180px|A sample of tetradymite Crystals are rhombohedral, but are rarely distinctly developed; they are twinned together in groups of four; hence the name of the mineral, from the Greek for fourfold. There is a perfect cleavage parallel to the basal plane and the mineral usually occurs in foliated masses of irregular outline. The color is steel-gray,

Stibarsen or allemontite is a natural form of arsenic antimonide (AsSb) or antimony arsenide (SbAs). The name stibarsen is derived from Latin stibium (antimony) and arsenic, whereas allemontite refers to the locality Allemont in France where the mineral was discovered. It is found in veins at Allemont, Isère, France; Valtellina, Italy; and the Comstock Lode, United States; and in a lithium pegmatites at Varuträsk, Sweden. Stibarsen is often mixed with pure arsenic or antimony, and the original description in 1941 proposed to use stibarsen for AsSb and allemontite for the mixtures. Since 1982,

Digenite is a copper sulfide mineral with formula: Cu9S5. Digenite is a black to dark blue opaque mineral that crystallizes with a trigonal–hexagonal scalenohedral structure. In habit it is usually massive, but does often show pseudo-cubic forms. It has poor to indistinct cleavage and a brittle fracture. It has a Mohs hardness of 2.5 to 3 and a specific gravity of 5.6. It is found in copper sulfide deposits of both primary and supergene occurrences. It is typically associated with and often intergrown with chalcocite, covellite, djurleite, bornite, chalcopyrite and pyrite. The type locality is

Svanbergite is a colorless, yellow or reddish mineral with the chemical formula SrAl3(PO4)(SO4)(OH)6. It has rhombohedral crystals.

Aerugite is a rare complex nickel arsenate mineral with a variably reported formula: Ni9(AsO4)2AsO6. It forms green to deep blue-green trigonal crystals. It has a Mohs hardness of 4 and a specific gravity of 5.85 to 5.95.

Clarkeite is a uranium oxide mineral with the chemical formula or .

Andersonite, Na2Ca(UO2)(CO3)3·6H2O, or hydrated sodium calcium uranyl carbonate is a rare uranium carbonate mineral that was first described in 1948. Named after Charles Alfred Anderson (1902–1990) of the United States Geological Survey, who first described the mineral species, it is found in sandstone-hosted uranium deposits. It has a high vitreous to pearly luster and is fluorescent. Andersonite specimens will usually glow a bright lemon yellow (or green with blue hints depending on the deposit) in ultraviolet light. It is commonly found as translucent small rhombohedral crystals that have a

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.

Osarizawaite is a greenish yellow sulfate mineral with the chemical formula: PbCuAl2(SO4)2(OH)6. It has rhombohedral crystals.

Stichtite is a mineral, a carbonate of chromium and magnesium; formula Mg6Cr2CO3(OH)16·4H2O. Its colour ranges from pink through lilac to a rich purple colour. It is formed as an alteration product of chromite-containing serpentine. It occurs in association with barbertonite (the hexagonal polymorph of Mg6Cr2CO3(OH)16·4H2O), chromite and antigorite.

Delafossite is a copper iron oxide mineral with formula CuFeO2 or Cu1+Fe3+O2. It is a member of the delafossite mineral group, which has the general formula ABO2, a group characterized by sheets of linearly coordinated A cations stacked between edge-shared octahedral layers (BO6). Delafossite, along with other minerals of the ABO2 group, is known for its wide range of electrical properties, its conductivity varying from insulating to metallic. Delafossite is usually a secondary mineral that crystallizes in association with oxidized copper and rarely occurs as a primary mineral.

Wassonite is a scarce titanium sulfide mineral with the chemical formula TiS. Its discovery was announced in a 2011 NASA press release as a single small grain within an enstatite chondrite meteorite called "Yamato 691", which was found during a 1969 Japanese expedition to Antarctica. This grain represents the first observation in nature of the synthetic compound titanium(II) sulfide.

Woodhouseite belongs to the beudantite group AB3(XO4)(SO4)(OH)6 where A = Ba, Ca, Pb or Sr, B = Al or Fe and X = S, As or P. Minerals in this group are isostructural with each other and also with minerals in the crandallite and alunite groups. They crystallise in the rhombohedral system with space group Rm and crystals are usually either tabular {0001} or pseudo-cubic to pseudo-cuboctahedral. Woodhouseite was named after Professor Charles Douglas Woodhouse (1888–1975), an American mineralogist and mineral collector from the University of California, Santa Barbara, US, and one-time General Mana

Valleriite is an uncommon sulfide mineral (hydroxysulfide) of iron and copper with formula: or . It is an opaque, soft, bronze-yellow to brown mineral which occurs as nodules or encrustations.

Herbertsmithite is a rhombohedral green-coloured mineral with chemical formula ZnCu3(OH)6Cl2. It is named after the mineralogist Herbert Smith (1872–1953) and was first found in 1972 in Chile. It is polymorphous with kapellasite and closely related to paratacamite. Herbertsmithite has also been found near Anarak, Iran, hence its other name, anarakite.

Arctite (Na2Ca4(PO4)3F) is a colourless mineral found in the Kola Peninsula northern Russia. Its IMA symbol is Arc. It has a Mohs hardness of 5 and has a specific gravity of 3.13. Arctite is transparent with a vitreous lustre. Arctite has a perfect cleavage and a trigonal crystal system. It is also a naturally occurring antiperovskite.

Fougèrite is a relatively recently described naturally occurring green rust mineral. It is the archetype of the fougèrite group in the larger hydrotalcite supergroup of naturally occurring layered double hydroxides. The structure is based on brucite-like layers containing Fe2+ and Fe3+ cations, O2− and OH− anions, with loosely bound [CO3]2− groups and H2O molecules between the layers. Fougèrite crystallizes in trigonal system. The ideal formula for fougèrite is [Fe2+4Fe3+2(OH)12][CO3]·3H2O. Higher degrees of oxidation produce the other members of the fougèrite group, namely trébeurdenite, [Fe2

Plumbogummite is a rare secondary lead phosphate mineral, belonging to the alunite supergroup of minerals, crandallite subgroup. Some other members of this subgroup are: Crandallite, CaAl3(PO4)2(OH)5·H2O, where calcium replaces lead Goyazite, SrAl3(PO4)2(OH)5·H2O, where strontium replaces lead Philipsbornite, PbAl3(AsO4)2(OH)5·H2O, where the arsenate group AsO4 replaces the phosphate group PO4

Rhodplumsite is a rare rhodium-lead sulfide mineral, chemical formula Rh3Pb2S2. It was originally discovered within a platinum nugget, in grains up to 40 μm in size. Its name originates from its composition; rhodium and lead (plumbum in Latin). Although this mineral contains large amounts of rhodium, it is not an economically viable ore of rhodium due to its rarity.

Zaïrite is a phosphate mineral with the chemical formula Bi(Fe3+,Al)3[(OH)6|(PO4)2]. The name was given from where it was locally discovered in Eta-Etu, Kivu, Congo (Zaïre) in 1975.

Segnitite is a lead iron(III) arsenate mineral. Segnitite was first found in the Broken Hill ore deposit in Broken Hill, New South Wales, Australia. In 1991, segnitite was approved as a new mineral. Segnitite has since been found worldwide near similar locality types where rocks are rich in zinc and lead especially. it was named for Australian mineralogist, gemologist and petrologist Edgar Ralph Segnit. The mineral was named after E. R. Segnit due to his contributions to Australian mineralogy.

Hidalgoite, PbAl3(AsO4)(SO4)(OH)4, is a rare member of the beudantite group and is usually classified as part of the alunite family. It was named after the place where it was first discovered, the Zimapán mining district, Hidalgo, Mexico. At Hidalgo where it was initially discovered, it was found as dense white masses in alternating dikes of quartz latite and quartz monzonite alongside other secondary minerals such as sphalerite, arsenopyrite, cerussite and trace amounts of angelsite and alamosite, it was then rediscovered at other locations such as Australia where it occurs on oxidized shear

Gurimite is a rare mineral with formula Ba3(VO4)2. It is a simple barium vanadate, one of the most simple barium minerals known. It is named after its type locality - Gurim anticline in Israel. It has formed in the rocks of the Hatrurim Formation. Gurimite's stoichiometry is similar to that of copper vanadates mcbirneyite and pseudolyonsite. An example of other barium vanadate mineral is tokyoite.

Shandite is a sulfide mineral with chemical formula: Ni3Pb2S2. It was discovered in 1948 by the German mineralogist Paul Raumdohr who named it named after Scottish petrologist, Samuel James Shand (1882–1957). Ramdohr characterized shandite by its metallic luster and a brass-yellow color. It has a specific gravity of 8.92, and a Mohs hardness value of 4. Shandite is commonly found as an inclusion in other minerals such as Heazelwoodite Ni3S2 or serpentine.

Amakinite (IMA symbol: Amk) is a semi transparent yellow-green hydroxide mineral belonging to the brucite group that was discovered in 1962. Its chemical formula is written as (Fe2+,Mg)(OH)2. It usually occurs in the form of splotchy, anhedral crystals forming within a group or structure in other minerals or rocks, such as kimberlite (occurring in diamond-rich eruptive pipe). Its composition is as follows:

Alluaivite is a rare mineral of the eudialyte group, with complex formula written as . It is unique among the eudialyte group as the only titanosilicate (other representatives of the group are usually zirconosilicates). The two dual-nature minerals of the group, being both titano- and zirconosilicates, are labyrinthite and dualite. They both contain alluaivite module in their structures. Alluaivite is named after Mt. Alluaiv in Lovozero Tundry massif, Kola Peninsula, Russia, where it is found in ultra-agpaitic, hyperalkaline pegmatites.

Motukoreaite is a mineral with formula Mg6Al3(OH)18[Na(H2O)6](SO4)2·6H2O (possibly more than one species). The mineral is named for Motukorea, the island in New Zealand where it was discovered. Motukoreaite was first noted in 1941 and officially described in 1977.

Geerite is a copper sulfide mineral with the chemical formula Cu8S5. The mineral is named after the original collector, Adam Geer, of Utica, New York, US.

Florencite-(Sm) is a very rare mineral of the plumbogummite group (alunite supergroup) with simplified formula SmAl3(PO4)2(OH)6. Samarium in florencite-(Sm) is substituted by other rare earth elements, mostly neodymium. It does not form separate crystals, but is found as zones in florencite-(Ce), which is cerium-dominant member of the plumbogummite group. Florencite-(Sm) is also a samarium-analogue of florencite-(La) (lanthanum-dominant) and waylandite (bismuth-dominant), both being aluminium-rich minerals.

Fengchengite is a rare mineral of the eudialyte group with the formula . The formula is simplified as it does not show the presence of cyclic silicate groups. When compared to other minerals of the group, fengchengite characterizes in the presence of ferric iron (thus similar to ikranite, mogovidite and feklichevite) and essential, site-dominating vacancies. The mineral was discovered in the Saima complex near Fengcheng city in China – hence its name.

Zadovite is an extremely rare mineral with formula BaCa6[(SiO4)(PO4)](PO4)2F. Together with its vanadium-analogue, aradite, zadovite occur in paralavas (type of pyrometamorphic rocks). Both minerals have structures similar to nabimusaite, and these three minerals occur in the Hatrurim Formation of Israel. Structure of all three minerals is related to that of hatrurite. Minerals combining barium, phosphorus and silicon together are scarce.

Lévyne or lévynite is a group of zeolite minerals, i.e. hydrated silicate minerals. There are two members of the group: Lévyne-Na, the sodium-dominant species , and Lévyne-Ca the calcium-dominant species

Waylandite is the phosphate analogue of arsenowaylandite and the aluminum analogue of zaïrite. The mineral was approved by the IMA in 1962, and was published the same year. Waylandite was named in honor of Edgar James Wayland. It is a member of the alunite supergroup, and a member of the plumbogummite – also known as crandallite – group. So far, only two bismuth-bearing members of the alunite supergroup are known, one of which is waylandite, alongside its ferric iron analogue zaïrite.