Vanadiocarpholite
Appearance
Vanadiocarpholite | |
---|---|
General | |
Category | Silicate mineral |
Formula (repeating unit) | Mn+2V+3AlSi2O6(OH)4 |
IMA symbol | Vcar[1] |
Strunz classification | 9.DB.05 |
Crystal system | Orthorhombic |
Crystal class | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
Space group | Ccca |
Unit cell | a = 13.83 Å, b = 20.681 Å c = 5.188 Å; Z = 8 |
Identification | |
Color | Pale-straw yellow, honey-yellow to brown |
Crystal habit | Prismatic to acicular crystal clusters, vein fillings |
Cleavage | Perfect on {010} |
Tenacity | Flexible |
Luster | Vitreous, silky |
Diaphaneity | Transparent |
Optical properties | Biaxial (+) |
Refractive index | nα=1.684, nβ=1.691, nγ=1.7 |
Birefringence | 0.0160 |
References | [2][3] |
Vanadiocarpholite (Mn+2V+3AlSi2O6(OH)4) is straw yellow to brown silicate mineral. It crystallizes in the orthorhombic crystal system. It is the vanadium rich variety of carpholite (Mn+2Al2Si2O6(OH)4).
Discovery and occurrence
[edit]It was first described in 2005 for an occurrence in the Molinello Mine, Graveglia Valley, Genova Province, Liguria, Italy.[3] It occurs in chert in a manganese ore deposit as vein fillings in silicified wood.[2]
Chemical composition
[edit]It consists of:[2]
Manganese | 15.56% | Mn | 20.09% | MnO |
Aluminium | 7.64% | Al | 14.44% | Al2O3 |
Vanadium | 14.43% | V | 21.23% | V2O3 |
Silicon | 15.91% | Si | 34.04% | SiO2 |
Hydrogen | 1.14% | H | 10.21% | H2O |
Oxygen | 45.32% | O |
References
[edit]- ^ 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.
- ^ a b c Vanadiocarpholite data on Webmineral.com
- ^ a b Vanadiocarpholite on Mindat.org