Andyrobertsite | |
---|---|
General | |
Category | Arsenate mineral |
Formula (repeating unit) | KCdCu5(AsO4)4(H2AsO4)·2H2O |
IMA symbol | Arb [1] |
Strunz classification | 8.DH.50 08 |
Dana classification | 42.09.02.03 |
Crystal system | Monoclinic |
Crystal class | Prismatic (2/m) (same H-M symbol) |
Space group | P21/m |
Unit cell | a = 9.81, b = 10.034 c = 9.975 [Å]; β = 101.83°; Z = 2 |
Identification | |
Color | Blue |
Crystal habit | Platy |
Cleavage | {100} good |
Mohs scale hardness | 3 |
Luster | Vitreous |
Streak | Pale blue |
Diaphaneity | Transparent |
Specific gravity | 4 |
Optical properties | Biaxial (-) |
Refractive index | nα = 1.72, nβ = 1.749, nγ = 1.757 |
Birefringence | δ = 0.037 |
References | [2] [3] |
Andyrobertsite is a rare, complex arsenate mineral with a blue color. It is found in the Tsumeb mine in Namibia and named after Andrew C. Roberts (b. 1950), mineralogist with the Geological Survey of Canada. A Ca-rich analogue (with Ca instead of Cd) is called calcioandyrobertsite and has a more greenish tint. [3]
Hornblende is a complex inosilicate series of minerals. It is not a recognized mineral in its own right, but the name is used as a general or field term, to refer to a dark amphibole. Hornblende minerals are common in igneous and metamorphic rocks.
Actinolite is an amphibole silicate mineral with the chemical formula Ca2(Mg4.5-2.5Fe2+0.5-2.5)Si8O22(OH)2.
Axinite is a brown to violet-brown, or reddish-brown bladed group of minerals composed of calcium aluminium boro-silicate, (Ca,Fe,Mn)3Al2BO3Si4O12OH. Axinite is pyroelectric and piezoelectric.
Anorthite is the calcium endmember of the plagioclase feldspar mineral series. The chemical formula of pure anorthite is CaAl2Si2O8. Anorthite is found in mafic igneous rocks. Anorthite is rare on the Earth but abundant on the Moon.
Augite is a common rock-forming pyroxene mineral with formula (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6. The crystals are monoclinic and prismatic. Augite has two prominent cleavages, meeting at angles near 90 degrees.
Zirkelite is an oxide mineral with the chemical formula (Ca,Th,Ce)Zr(Ti,Nb)2O7. It occurs as well-formed fine sized isometric crystals. It is a black, brown or yellow mineral with a hardness of 5.5 and a specific gravity of 4.7.
Chabazite is a tectosilicate mineral of the zeolite group, closely related to gmelinite, with the chemical formula (Ca,K
2,Na
2,Mg)Al
2Si
4O
12•6H
2O. Recognized varieties include Chabazite-Ca, Chabazite-K, Chabazite-Na, and Chabazite-Sr, depending on the prominence of the indicated cation.
Ankerite is a calcium, iron, magnesium, manganese carbonate mineral of the group of rhombohedral carbonates with the chemical formula Ca(Fe,Mg,Mn)(CO3)2. In composition it is closely related to dolomite, but differs from this in having magnesium replaced by varying amounts of iron(II) and manganese. It forms a series with dolomite and kutnohorite.
Braunite is a silicate mineral containing both di- and tri-valent manganese with the chemical formula: Mn2+Mn3+6[O8|SiO4]. Common impurities include iron, calcium, boron, barium, titanium, aluminium, and magnesium.
Paragonite is a mineral, related to muscovite. Its empirical formula is NaAl2(AlSi3O10)(OH)2. A wide solvus separates muscovite from paragonite, such that there is little solid solution along the vector Na+K+ and apparent micas of intermediate composition is most commonly a microscopic (or even sub-microscopic) intergrowth of two distinct micas, one rich in K, and the other in Na. Paragonite is a common mineral in rocks metamorphosed under blueschist facies conditions along with other sodic minerals such as albite, jadeite and glaucophane. During the transition from blueschist to greenschist facies, paragonite and glaucophane are transformed into chlorite and albite. Jadeite bearing pyroxene minerals have suggested Clinozoisite and paragonite are associated and derived from lawsonite releasing Quartz and water via the following reaction:
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.
Aeschynite-(Y) is a rare earth mineral of yttrium, calcium, iron, thorium, titanium, niobium, oxygen, and hydrogen with the chemical formula (Y,Ca,Fe,Th)(Ti,Nb)2(O,OH)6. Its name comes from the Greek word for "shame". Its Mohs scale rating is 5 to 6.
Cancrinite is a complex carbonate and silicate of sodium, calcium and aluminium with the formula Na6Ca2[(CO3)2|Al6Si6O24]·2H2O. It is classed as a member of the feldspathoid group of minerals; the alkali feldspars that are poor in silica. Yellow, orange, pink, white or even blue, it has a vitreous or pearly luster; a hardness of 5–6 and an uneven conchoidal fracture. It is unusual among the silicate minerals in that it will effervesce with hydrochloric acid due to the associated carbonate ions.
Calderite is a mineral in the garnet group with the chemical formula (Mn2+, Ca)3(Fe3+, Al)2(SiO4)3.
Zirconolite is a mineral, calcium zirconium titanate; formula CaZrTi2O7. Some examples of the mineral may also contain thorium, uranium, cerium, niobium and iron; the presence of thorium or uranium would make the mineral radioactive. It is black or brown in color.
Aliettite is a complex phyllosilicate mineral of the smectite group with a formula of (Ca0.2Mg6(Si,Al)8O20(OH)4·4H2O) or [Mg3Si4O10(OH)2](Ca0.5,Na)0.33(Al,Mg,Fe2+)2-3(Si,Al)4O10(OH)2·n(H2O).
Piemontite is a sorosilicate mineral in the monoclinic crystal system with the chemical formula Ca2(Al,Mn3+,Fe3+)3(SiO4)(Si2O7)O(OH). It is a member of the epidote group.
Larnite is a calcium silicate mineral with formula: Ca2SiO4. It is the calcium member of the olivine group of minerals.
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.
Crandallite is a calcium aluminium basic phosphate mineral. It has ideal formula CaAl
3(PO
4)
2(OH)
5·H
2O. Crandallite was named after Milan L. Crandall, Jr, who worked for Knight Syndicate. This mineral is found in laterite and in alteration products of phosphate rich pegmatites.