Zincoberaunite | |
---|---|
General | |
Category | Phosphate minerals |
Formula (repeating unit) | ZnFe3+5(OH)5(PO4)4·4H2O |
IMA symbol | Zbru [1] |
Crystal system | Monoclinic |
Crystal class | Prismatic (2/m) (same H-M symbol) |
Space group | C2/c |
Unit cell | a = 20.837(2) Å, b = 5.1624(4) Å, c = 19.250(1) Å; β = 93.252(5)° |
Identification | |
Color | Light gray, light greenish yellow |
Crystal habit | Fiber, capillary or prismatic microcrystals |
Mohs scale hardness | 3–4 |
Luster | VSilky, vitreous |
Diaphaneity | Translucent |
Specific gravity | 2.94 |
Optical properties | Biaxial (+) |
Refractive index | nα = 1.745 nβ = 1.760 nγ = 1.770 |
Birefringence | δ = 0.025 |
2V angle | Measured: 80° |
References | [2] |
Zincoberaunite is an iron and zinc phosphate mineral, the Zn analogue of beraunite. It was first described by Chukanov et al. for an occurrence in Hagendorf Sud pegmatite in Germany. [3] Zincoberaunite occurs as a secondary mineral as an alteration product of primary phosphate minerals in granite pegmatites.
Beraunite crystallizes in the monoclinic crystal system with point group 2/m. Beraunite's formula is Zn Fe3+5(OH)5(PO4)4·4H2O.
Zincoberaunite has been located so far in two localities in the world, the type locality, and Krasno, near Horní Slavkov (Czech Republic). It appears in two paragenesis, as an alteration of other phosphates in pegmatites: in one with jungle, phosphophyllite and mitridatite and in another with flurlite, plimerite, beraunite rich in zinc, schoonerite, parascholzite, robertsite and altered phosphophyllite. However, it is likely that a detailed study of the zinc-rich beraunite specimens will allow locating other localities for the zincoberaunite.
Zincoberaunite contains Zn instead of ferrous iron. Before it was characterized as an independent species, specimens with a high zinc content had been found, but since the iron content was higher, they had been considered as varieties. In addition to the elements indicated in the formula, it contains small amounts of magnesium and calcium. In the type locality it appears as pale gray capillary microcrystals forming silky-looking aggregates. In a second locality it has been found as prismatic microcrystals with compositional zoning. [4]
Vivianite (Fe2+
3(PO
4)
2·8H
2O) is a hydrated iron phosphate mineral found in a number of geological environments. Small amounts of manganese Mn2+, magnesium Mg2+, and calcium Ca2+ may substitute for iron Fe2+ in the structure. Pure vivianite is colorless, but the mineral oxidizes very easily, changing the color, and it is usually found as deep blue to deep bluish green prismatic to flattened crystals.
Vivianite crystals are often found inside fossil shells, such as those of bivalves and gastropods, or attached to fossil bone.
Brazilianite, whose name derives from its country of origin, Brazil, is a typically yellow-green phosphate mineral, most commonly found in phosphate-rich pegmatites.
Lithiophilite is a mineral containing the element lithium. It is lithium manganese(II) phosphate with chemical formula LiMnPO4. It occurs in pegmatites often associated with triphylite, the iron end member in a solid solution series. The mineral with intermediate composition is known as sicklerite and has the chemical formula Li(Mn,Fe)PO4). The name lithiophilite is derived from the Greek philos (φιλός) "friend", as lithiophilite is usually found with lithium.
Segelerite is a complex phosphate mineral with formula CaMgFe3+OH(PO4)2·H2O. It occurs in pegmatites and forms striking green or chartreuse crystals. It was discovered in 1974 in the Black Hills of South Dakota by an amateur mineralogist from New York, Curt G. Segeler (1901–1989), after whom it is named.
Zanazziite is a complex hydrated phosphate mineral from the roscherite group. It is a magnesium beryllium phosphate mineral. Zanazziite arises as barrel-shaped crystals and can reach up to 4 mm. It grows alongside quartz minerals. It is found in the crevices of Lavra da Ilha pegmatite, near Taquaral, in northeastern Minas Gerais, Brazil. Zanazziite is named after Pier F. Zanazzi. Zanazziite has an ideal chemical formula of Ca2Mg5Be4(PO4)6(OH)4·6H2O.
Robertsite, Ca3(Mn3+)4[(OH)3| (PO4)2]2·3(H2O) (alternatively formulated Ca2(Mn3(PO4)3O2)(H2O)3), is a secondary phosphate mineral named for Willard Lincoln Roberts (1923–1987), mineralogist and professor at South Dakota School of Mines in Rapid City, South Dakota.
Aheylite is a rare phosphate mineral with formula (Fe2+Zn)Al6[(OH)4|(PO4)2]2·4(H2O). It occurs as pale blue to pale green triclinic crystal masses. Aheylite was made the newest member of the turquoise group in 1984 by International Mineralogical Association Commission on New Minerals and Mineral Names.
Phosphophyllite (from Ancient Greek phyllon 'leaf', and phosphate) is a rare mineral with the chemical formula Zn2Fe(PO4)2·4H2O, composed of hydrated zinc phosphate. It is highly prized by collectors for its rarity and for its delicate bluish green colour. Phosphophyllite is rarely cut because it is fragile and brittle, and large crystals are too valuable to be broken up.
Arthurite is a mineral composed of divalent copper and iron ions in combination with trivalent arsenate, phosphate and sulfate ions with hydrogen and oxygen. Initially discovered by Sir Arthur Russell in 1954 at Hingston Down Consols mine in Calstock, Cornwall, England, arthurite is formed as a resultant mineral in the oxidation region of some copper deposits by the variation of enargite or arsenopyrite. The chemical formula of Arthurite is CuFe23+(AsO4,PO4,SO4)2(O,OH)2·4H2O.
Beraunite is an iron phosphate mineral. It was first described by August Breithaupt for an occurrence in Beraun currently in the Czech Republic. Beraunite occurs as a secondary mineral in iron ore deposits, and as an alteration product of primary phosphate minerals in granite pegmatites.
Cyrilovite (NaFe33+(PO4)2(OH)4·2(H2O)) is a hydrous sodium iron phosphate mineral. It is isomorphous and isostructural with wardite, the sodium aluminium counterpart.
Hureaulite is a manganese phosphate with the formula Mn2+5(PO3OH)2(PO4)2·4H2O. It was discovered in 1825 and named in 1826 for the type locality, Les Hureaux, Saint-Sylvestre, Haute-Vienne, Limousin, France. It is sometimes written as huréaulite, but the IMA does not recommend this for English language text.
Zinclipscombite is a dark-green to brown zinc iron phosphate mineral with the formula Zn(Fe3+)2(PO4)2(OH)2. It occurs as fibrous spheres and exhibits tetragonal crystal structure.
Tarbuttite is a rare phosphate mineral with formula Zn2(PO4)(OH). It was discovered in 1907 in what is now Zambia and named for Percy Coventry Tarbutt.
Greifensteinite is beryllium phosphate mineral with formula: Ca2Fe2+5Be4(PO4)6(OH)4·6H2O. It is the Fe2+ dominant member of the roscherite group. It crystallizes in the monoclinic crystal system and typically forms prismatic dark olive green crystals.
Falsterite is a rare phosphate mineral with the formula Ca2MgMn2+2(Fe2+0.5Fe3+0.5)4Zn4(PO4)8(OH)4(H2O)14. It is a pegmatitic mineral, related to the currently approved mineral ferraioloite.
Steinmetzite is a very rare phosphate mineral with formula Zn2Fe(PO4)2(OH)•3H2O. It was discovered among pegmatites of Hagendorf in Germany, that are famous for rare phosphate minerals. Steinmetzite is chemically related to phosphophyllite and other zinc iron phosphates, namely plimerite and zinclipscombite.
Serrabrancaite is a mineral with the chemical formula MnPO4•H2O and which is named for the locality where it was found, the Alto Serra Branca Pegmatite. The Alto Serra Branca mine has been in operation since the 1940s. It is located in Paraiba, Brazil near a village named Pedra Lavrada. Tantalite is the main mineral mined here. Specimens of serrabrancaite are kept in the Mineralogical Collections of both the Bergakademie Freiberg, Germany and the Martin-Luther Universität Halle, Institut für Geologische Wissenschaften.
Strunzite (Mn2+Fe3+2(PO4)2(OH)2{{·}}6H2O) is a light yellow mineral of the strunzite group, first discovered in 1957.
Rockbridgeite is an anhydrous phosphate mineral in the "Rockbridgeite" supergroup with the chemical formula Fe2+Fe3+4(PO4)3(OH)5. It was discovered at the since-shut-down Midvale Mine in Rockbridge County, Virginia, United States. The researcher who first identified it, Clifford Frondel, named it in 1949 for its region of discovery, Rockbridge County.
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