Nacrite | |
---|---|
General | |
Category | Phyllosilicates Kaolinite-serpentine group |
Formula (repeating unit) | Al2Si2O5(OH)4 |
IMA symbol | Ncr [1] |
Strunz classification | 9.ED.05 |
Crystal system | Monoclinic |
Crystal class | Domatic (m) (same H-M symbol) |
Space group | Cc |
Identification | |
References | [2] [3] |
Nacrite Al 2 Si 2 O 5(OH)4 is a clay mineral that is polymorphous (or polytypic) with kaolinite. [4] [5] It crystallizes in the monoclinic system. X-ray diffraction analysis is required for positive identification.
Nacrite was first described in 1807 for an occurrence in Saxony, Germany. The name is from nacre in reference to the dull luster of the surface of nacrite masses scattering light with slight iridescences resembling those of the mother of pearls secreted by oysters.
Lazurite, old name Azure spar is a tectosilicate mineral with sulfate, sulfur and chloride with formula (Na,Ca)8[(S,Cl,SO4,OH)2|(Al6Si6O24)]. It is a feldspathoid and a member of the sodalite group. Lazurite crystallizes in the isometric system although well‐formed crystals are rare. It is usually massive and forms the bulk of the gemstone lapis lazuli.
Cinnabar, or cinnabarite, also known as mercurblende is the bright scarlet to brick-red form of mercury(II) sulfide (HgS). It is the most common source ore for refining elemental mercury and is the historic source for the brilliant red or scarlet pigment termed vermilion and associated red mercury pigments.
Tusionite is a rare colorless to transparent to translucent yellow brown trigonal borate mineral with chemical formula: MnSn(BO3)2. The mineral is composed of 18.86% manganese, 40.76% tin, 7.42% boron, and 32.96% oxygen. It is a late stage hydrothermal mineral and occurs rarely in granite pegmatites in miarolitic cavities.
Annabergite is an arsenate mineral consisting of a hydrous nickel arsenate. It is considered a member of the vivianite group and known for its ability to form crystals in a characteristic apple-green color.
Abenakiite-(Ce) is a mineral of sodium, cerium, neodymium, lanthanum, praseodymium, thorium, samarium, oxygen, sulfur, carbon, phosphorus, and silicon with a chemical formula Na26Ce6(SiO3)6(PO4)6(CO3)6(S4+O2)O. The silicate groups may be given as the cyclic Si6O18 grouping. The mineral is named after the Abenaki, an Algonquian Indian tribe of New England. Its Mohs scale rating is 4 to 5.
Aeschynite-(Ce) is a rare earth mineral of cerium, calcium, iron, thorium, titanium, niobium, oxygen, and hydrogen with chemical formula (Ce,Ca,Fe,Th)(Ti,Nb)2(O,OH)6. Its name comes from the Greek word αισχύνη ("aeschyne") for "shame" because early chemists had difficulty with separations of titanium from zirconium.
Scorodite is a common hydrated iron arsenate mineral, with the chemical formula FeAsO4·2H2O. It is found in hydrothermal deposits and as a secondary mineral in gossans worldwide. Scorodite weathers to limonite.
Xifengite (Fe5Si3) is a rare metallic iron silicide mineral. The crystal system of xifengite is hexagonal. It has a specific gravity of 6.45 and a Mohs hardness of 5.5. It occurs as steel gray inclusions within other meteorite derived nickel iron mineral phases.
Zakharovite is a mineral, a silicate of sodium and manganese; formula Na4Mn5Si10O24(OH)6·6H2O. It has a yellow colour with a pearly lustre. Discovered in 1982 in the Kola peninsula of Northern Russia, it is named after Evgeny Evgenevich Zakharov (1902–1980), the director of the Moscow Institute of Geological Exploration.
Agrellite (NaCa2Si4O10F) is a rare triclinic inosilicate mineral with four-periodic single chains of silica tetrahedra.
Neptunite is a silicate mineral with the formula KNa2Li(Fe2+, Mn2+)2Ti2Si8O24. With increasing manganese it forms a series with mangan-neptunite. Watatsumiite is the variety with vanadium replacing the titanium in the formula.
Loparite-(Ce) is a granular, brittle oxide mineral of the perovskite class. It is black to dark grey and may appear grey to white in reflected light on polished thin section with reddish brown internal reflections. It has the chemical formula of (Ce,Na,Ca)(Ti,Nb)O3. Nioboloparite is a variation of loparite-(Ce) containing niobium.
Brownleeite is a silicide mineral with chemical formula MnSi. It was discovered by researchers of the Johnson Space Center in Houston while analyzing the Pi Puppid particle shower of the comet 26P/Grigg-Skjellerup. The only other known natural manganese silicide is mavlyanovite, Mn5Si3.
Kaersutite is a dark brown to black double-chain calcic titanium-bearing amphibole mineral with formula: NaCa2(Mg3Ti4+Al)(Si6Al2)O22(O)2.
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.
Heptasartorite is a very rare mineral with formula Tl7Pb22As55S108. It belongs to sartorite homologous series. It is related to other recently approved minerals of the series: enneasartorite and hendekasartorite. All three minerals come from a quarry in Lengenbach, Switzerland, which is famous of thallium minerals. Chemically similar minerals include edenharterite and hutchinsonite.
Faizievite is a very rare mineral with the formula K2Na(Ca6Na)Ti4Li6Si24O66F2. This triclinic mineral is chemically related to baratovite and katayamalite. Faizievite is a single-locality mineral, coming from the moraine of the Darai-Pioz glacier, Tien Shan Mountains, Tajikistan. Alkaline rocks of this site are famous for containing numerous rare minerals, often enriched in boron, caesium, lithium, titanium, rare earth elements, barium, and others.
Hexacelsian is a rare barium silicate mineral with the formula BaAl2Si2O8. It was discovered in the Hatrurim Basin in Israel, where the Hatrurim Formation of rocks formed due to exposed pyrometamorphism.
Manganiceladonite is a rare silicate mineral with the formula KMgMn3+Si4O10(OH)2. It is one of many minerals discovered in the Cerchiara mine, La Spezia, Liguria, Italy.
The sulfate fluorides are double salts that contain both sulfate and fluoride anions. They are in the class of mixed anion compounds. Some of these minerals are deposited in fumaroles.