Ajoite | |
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Ajoite from Arizona (size: 2.4×2.4×2.0 cm)
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General | |
Category | Silicate mineral |
Formula (repeating unit) |
(Na,K)Cu7AlSi9O24(OH)6.3H2O |
Strunz classification | 9.EA.70 (10 ed) 8/D.07-10 (8 ed) |
Dana classification | 78.05.01.011 |
Crystal system | Triclinic |
Crystal class | Pinacoidal (1) (same H-M symbol) |
Space group | P1 |
Unit cell | a = 13.63, b = 14.5 c = 13.62 [Å]; α = 107.16° β = 105.45°, γ = 110.57°; Z = 1 |
Identification | |
Color | Bluish green |
Crystal habit | Sprays of bladed prismatic crystals |
Cleavage | Perfect on {010} |
Mohs scale hardness | 3½ |
Luster | Vitreous |
Streak | Greenish white |
Diaphaneity | Translucent |
Specific gravity | 2.96 |
Optical properties | Biaxial (+) |
Refractive index | nα = 1.550, nβ = 1.583, nγ = 1.641 |
Birefringence | δ = 0.091 |
Pleochroism | X: very light bluish green; Y and Z: brilliant bluish green |
2V angle | Measured: 68° to 80° |
Solubility | Decomposed by acids |
References |
Ajoite is a hydrated sodium potassium copper aluminium silicate hydroxide mineral. Ajoite has the chemical formula , and minor Mn, Fe and Ca are usually also present in the structure. Ajoite is used as a minor ore of copper.