Scorzalite
| Scorzalite | |
|---|---|
Scorzalite from the Estaño Orcko mine, Potosí Department, Bolivia (6.8 x 5.7 x 5.1 cm) | |
| General | |
| Category | Phosphate minerals |
| Formula | (Fe2+,Mg)Al2(OH,PO4)2 |
| IMA symbol | Scz |
| Strunz classification | 8.BB.40 |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H-M symbol) |
| Space group | P2/c |
| Unit cell | a = 7.15 Å, b = 7.31 Å c = 7.25 Å; β = 120.58°; Z = 2 |
| Identification | |
| Color | Dark blue |
| Crystal habit | Granular, massive, dipyramidal crystals |
| Twinning | Multiple, lamellar |
| Cleavage | Good on {110}, indistinct on {101} |
| Fracture | Uneven |
| Mohs scale hardness | 6 |
| Luster | Vitreous |
| Streak | White |
| Diaphaneity | Semitransparent |
| Specific gravity | 3.33 |
| Optical properties | Biaxial (−) |
| Refractive index | nα = 1.626 – 1.645 nβ = 1.654 – 1.674 nγ = 1.663 – 1.680 |
| Birefringence | δ = 0.037 |
| Pleochroism | Visible X = colorless; Y = Z = blue |
| 2V angle | Measured: 62° |
| Dispersion | r < v perceptible |
| References | |
Scorzalite ((Fe2+,Mg)Al2(OH,PO4)2) is a dark blue phosphate mineral containing iron, magnesium, and aluminium phosphate. Scorzalite forms one endmember of a solid solution series with the lighter, more magnesium-rich lazulite.
Scorzalite crystallizes in the monoclinic system in a dipyramidal form. It has a Mohs hardness of 5.5–6 and a specific gravity of 3.4. It is infusible and insoluble in water, and only slightly soluble in warm hydrochloric acid.