Junitoite
| Junitoite | |
|---|---|
Vitreous to pearly junitoite crystals to 4 mm from the Christmas Mine in Gila County, Arizona | |
| General | |
| Category | Sorosilicate |
| Formula | CaZn2Si2O7·H2O |
| IMA symbol | Jit |
| Strunz classification | 9.BD.15 |
| Dana classification | 56.2.1.1 |
| Crystal system | Orthorhombic |
| Crystal class | Pyramidal (mm2) H-M group: (mm2) |
| Space group | Ama2 |
| Unit cell | a = 12.510(7) b = 6.318(3) c = 8.561(6) [Å]; Z = 4 |
| Identification | |
| Color | Colorless, milk-white, or colored due to alteration |
| Cleavage | Good on {100}; poor on {010} and {011} |
| Fracture | Micaceous |
| Tenacity | Brittle to semi-sectile due to alteration |
| Mohs scale hardness | 4.5 |
| Luster | Adamantine, Vitreous, Sub-Vitreous |
| Streak | Colorless |
| Diaphaneity | Transparent to translucent |
| Optical properties | Biaxial (+) |
| Refractive index | nα = 1.656 nβ = 1.664 nγ = 1.672 |
| Birefringence | δ = 0.016 |
| 2V angle | Measured: 86°, Calculated: 88° |
| References | |
Junitoite is a mineral with formula CaZn2Si2O7·H2O. It was discovered at the Christmas mine in Christmas, Arizona, and described in 1976. The mineral is named for mineral chemist Jun Ito (1926–1978).