Ashburtonite
From Wikipedia, the free encyclopedia
| Ashburtonite | |
|---|---|
| General | |
| Category | Cyclosilicates |
| Formula | HPb4Cu4Si4O12(HCO3)4(OH)4Cl |
| IMA symbol | Ahb[1] |
| Strunz classification | 9.CF.05 |
| Crystal system | Tetragonal |
| Crystal class | Dipyramidal (4/m) H-M symbol: (4/m) |
| Space group | I4/m |
| Unit cell | a = 14.23, c = 6.1 [Å]; Z = 2 |
| Identification | |
| Color | Blue |
| Crystal habit | Prismatic, needle like in clusters |
| Cleavage | None |
| Fracture | Conchoidal |
| Tenacity | Brittle |
| Luster | Vitreous to adamantine |
| Streak | light blue |
| Diaphaneity | Transparent |
| Specific gravity | Greater than 4.07, calculated 4.69 |
| Optical properties | Uniaxial (+) |
| Refractive index | nω = 1.786 nε = 1.800 |
| Birefringence | 0.0140 |
| References | [2][3][4][5] |
Ashburtonite is a rare lead copper silicate-bicarbonate mineral with formula: HPb4Cu2+4Si4O12(HCO3)4(OH)4Cl.[5]