Calciborite
Calciborite | |
---|---|
General | |
Category | Inoborates |
Formula (repeating unit) | CaB2O4 |
IMA symbol | Cbo[1] |
Strunz classification | 6.BC.10 |
Crystal system | Orthorhombic |
Crystal class | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
Space group | Pccn |
Unit cell | a = 8.38 Å, b = 13.82 Å, c = 5.00 Å; Z = 8 |
Identification | |
Formula mass | 125.70 g/mol |
Color | White |
Crystal habit | Prismatic crystals and radial clusters |
Cleavage | None |
Fracture | Conchoidal to uneven |
Mohs scale hardness | 3.5 |
Luster | Vitreous |
Streak | White |
Diaphaneity | Translucent |
Specific gravity | 2.878 |
Optical properties | Biaxial (-) |
Refractive index | nα = 1.595 nβ = 1.654 nγ = 1.670 |
Birefringence | δ = 0.075 |
2V angle | Measured: 54° |
References | [2][3][4][5] |
Calciborite, CaB2O4, is a rare calcium borate mineral.
It was first described in 1955 in the Novofrolovskoye copper–boron deposit, near Krasnoturinsk, Turinsk district, Northern Ural Mountains, Russia.[4] It occurs in a skarn deposit formed in limestone adjacent to a quartz diorite intrusive. It occurs associated with: sibirskite (another rare calcium borate mineral), calcite, dolomite, garnet, magnetite and pyroxene.[5] It has also been reported from the Fuka mine of Okayama Prefecture, Japan.[4]
References
- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ Mineralienatlas
- ^ Calciborite Mineral Data from Webmineral
- ^ a b c Calciborite: Calciborite mineral information from Mindat.org
- ^ a b Handbook of Mineralogy