Scorzalite | |
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General | |
Category | Phosphate minerals |
Formula (repeating unit) | (Fe2+,Mg)Al2(OH,PO4)2 |
IMA symbol | Scz[1] |
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 | [2][3][4] |
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.