Andorite | |
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General | |
Category | Sulfosalt mineral |
Formula (repeating unit) | PbAgSb3S6 |
IMA symbol | Ado [1] |
Strunz classification | 2.JB.40a |
Crystal system | Orthorhombic |
Crystal class | Pyramidal (mm2) H-M symbol: (mm2) |
Space group | Pn21a (andorite VI, senandorite) |
Unit cell | a = 12.99, b = 19.14, c = 4.3 [Å]; Z = 4 |
Identification | |
Color | Dark steel-gray, may tarnish yellow or iridescent; white in polished section |
Crystal habit | Crystals stout prismatic to tabular on {100}, striations parallel to [001]; massive |
Twinning | On {110} |
Cleavage | none observed |
Fracture | conchoidal |
Mohs scale hardness | 3 – 3.5 |
Luster | metallic |
Streak | Black |
Diaphaneity | Opaque |
Specific gravity | 5.33 – 5.37 |
Optical properties | anisotropic |
References | [2] [3] |
Andorite is a sulfosalt mineral with the chemical formula PbAgSb3S6.
It was first described in 1892 for an occurrence in the Baia Sprie mine, Baia Sprie, in what is now Maramureș County, Romania, and named for Hungarian amateur mineralogist Andor von Semsey (1833–1923). [2] [4] Andorite occurs in low-temperature polymetallic hydrothermal veins. It occurs associated with stibnite, sphalerite, baryte, fluorite, siderite, cassiterite, arsenopyrite, stannite, zinkenite, tetrahedrite, pyrite, alunite, quartz, pyrargyrite, stephanite and rhodochrosite. [3]
Baryte, barite or barytes ( or ) is a mineral consisting of barium sulfate (BaSO4). Baryte is generally white or colorless, and is the main source of the element barium. The baryte group consists of baryte, celestine (strontium sulfate), anglesite (lead sulfate), and anhydrite (calcium sulfate). Baryte and celestine form a solid solution (Ba,Sr)SO4.
Baia Sprie is a town in Maramureș County, northern Romania. Baia Sprie is situated at a distance of 9 km (5.6 mi) from Baia Mare and belongs to the Baia Mare metropolitan area.
Smithsonite, also known as zinc spar, is the mineral form of zinc carbonate (ZnCO3). Historically, smithsonite was identified with hemimorphite before it was realized that they were two different minerals. The two minerals are very similar in appearance and the term calamine has been used for both, leading to some confusion. The distinct mineral smithsonite was named in 1832 by François Sulpice Beudant in honor of English chemist and mineralogist James Smithson (c. 1765–1829), who first identified the mineral in 1802.
Boehmite or böhmite is an aluminium oxide hydroxide mineral, a component of the aluminium ore bauxite. It is dimorphous with diaspore. It crystallizes in the orthorhombic dipyramidal system and is typically massive in habit. It is white with tints of yellow, green, brown or red due to impurities. It has a vitreous to pearly luster, a Mohs hardness of 3 to 3.5 and a specific gravity of 3.00 to 3.07. It is colorless in thin section, optically biaxial positive with refractive indices of nα = 1.644 – 1.648, nβ = 1.654 – 1.657 and nγ = 1.661 – 1.668.
Samarskite is a radioactive rare earth mineral series which includes samarskite-(Y), with the chemical formula (YFe3+Fe2+U,Th,Ca)2(Nb,Ta)2O8 and samarskite-(Yb), with the chemical formula (YbFe3+)2(Nb,Ta)2O8. The formula for samarskite-(Y) is also given as (Y,Fe3+,U)(Nb,Ta)O4.
Cooperite is a grey mineral consisting of platinum sulfide, generally in combinations with sulfides of other elements such as palladium and nickel. Its general formula is (Pt,Pd,Ni)S. It is a dimorph of braggite.
Bournonite is a sulfosalt mineral species, trithioantimoniate of lead and copper with the formula PbCuSbS3.
Illite, also called hydromica or hydromuscovite, is a group of closely related non-expanding clay minerals. Illite is a secondary mineral precipitate, and an example of a phyllosilicate, or layered alumino-silicate. Its structure is a 2:1 sandwich of silica tetrahedron (T) – alumina octahedron (O) – silica tetrahedron (T) layers. The space between this T-O-T sequence of layers is occupied by poorly hydrated potassium cations which are responsible for the absence of swelling. Structurally, illite is quite similar to muscovite with slightly more silicon, magnesium, iron, and water and slightly less tetrahedral aluminium and interlayer potassium. The chemical formula is given as (K,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2·(H2O)], but there is considerable ion (isomorphic) substitution. It occurs as aggregates of small monoclinic grey to white crystals. Due to the small size, positive identification usually requires x-ray diffraction or SEM-EDS analysis. Illite occurs as an altered product of muscovite and feldspar in weathering and hydrothermal environments; it may be a component of sericite. It is common in sediments, soils, and argillaceous sedimentary rocks as well as in some low grade metamorphic rocks. The iron-rich member of the illite group, glauconite, in sediments can be differentiated by x-ray analysis.
The Săsar is a right tributary of the river Lăpuș in Maramureș County, Romania. It discharges into the Lăpuș in Bozânta Mare, southwest of Baia Mare. It is a medium-size river which flows through the cities of Baia Sprie and Baia Mare. Its length is 31 km (19 mi) and its basin size is 306 km2 (118 sq mi).
Boulangerite is an uncommon monoclinic orthorhombic sulfosalt mineral, lead antimony sulfide, formula Pb5Sb4S11. It was named in 1837 in honor of French mining engineer Charles Boulanger (1810–1849), and had been a valid species since pre-IMA. It was first described prior to 1959, and is now grandfathered.
Chlorargyrite is the mineral form of silver chloride (AgCl). Chlorargyrite occurs as a secondary mineral phase in the oxidation of silver mineral deposits. It crystallizes in the isometric–hexoctahedral crystal class. Typically massive to columnar in occurrence it also has been found as colorless to variably yellow cubic crystals. The color changes to brown or purple on exposure to light. It is quite soft with a Mohs hardness of 1 to 2 and dense with a specific gravity of 5.55. It is also known as cerargyrite and, when weathered by desert air, as horn silver. Bromian chlorargyrite is also common. Chlorargyrite is water-insoluble.
Microlite was once known as a pale-yellow, reddish-brown, or black isometric mineral composed of sodium calcium tantalum oxide with a small amount of fluorine. Its chemical formula is(Na,Ca)2Ta2O6(O,OH,F). Today it is a name of a group of oxide minerals of a similar stoichiometry having tantalum prevailing over titanium and niobium. The microlite group belongs to a large pyrochlore supergroup that occurs in pegmatites and constitutes an ore of tantalum. It has a Mohs hardness of 5.5 and a variable specific gravity of 4.2 to 6.4. It occurs as disseminated microscopic subtranslucent to opaque octahedral crystals with a refractive index of 2.0 to 2.2. Microlite is also called djalmaite, but both names are now obsolete.
Augelite is an aluminium phosphate mineral with formula: Al2(PO4)(OH)3. The shade varies from colorless to white, yellow or rose. Its crystal system is monoclinic.
Vantasselite is a rare aluminium phosphate mineral with formula: Al4(PO4)3(OH)3 •9H2O. It crystallizes in the orthorhombic system and has a white color, a hardness of 2 to 2.5, a white streak and a pearly luster.
Santabarbaraite is an amorphous ferric hydroxy phosphate mineral hydrate that was discovered in Tuscany, Italy during 2000. It also can be found in Victoria, Australia and Lake Baikal, Siberia.
Pargasite is a complex inosilicate mineral of the amphibole group with formula NaCa2(Mg4Al)(Si6Al2)O22(OH)2.
Semseyite is a rarely occurring sulfosalt mineral and is part of the class of lead antimony sulfides. It crystallizes in the monoclinic system with the chemical composition Pb9Sb8S21. The mineral forms dark gray to black aggregates.
Imogolite is an aluminium silicate clay mineral with the chemical formula Al2SiO3(OH)4. It occurs in soils formed from volcanic ash and was first described in 1962 for an occurrence in Uemura, Kumamoto prefecture, Kyushu Region, Japan. Its name originates from the Japanese word imogo, which refers to the brownish yellow soil derived from volcanic ash. It occurs together with allophane, quartz, cristobalite, gibbsite, vermiculite and limonite.
Felsőbányaite or basaluminite is a hydrated aluminium sulfate mineral with formula: Al4(SO4)(OH)10·4H2O. It is a rare white to pale yellow mineral which typically occurs as globular masses and incrustations or as minute rhombic crystals. It crystallizes in the monoclinic crystal system.
Fülöppite is a rare member of the plagionite group, comprising heteromorphite Pb7Sb8S19, plagionite Pb5Sb8S17 and semseyite Pb9Sb8S21. It was named in 1929 for Dr. Béla Fülöpp (1863–1938), a Hungarian lawyer, statesman and mineral collector.