Schlossmacherite

secondary mineral in the oxidized zone of a copper-bearing gold deposit at the Emma Luisa gold mine, Guanaco district, about 100 km east-northeast of Taltal, Antofagasta, Chile. This is the only location in the world for Schlossmacherite. It is found as polycrystalline aggregates and crusts of pale green to grayish green.

Chemical Formula: (H3O,Ca)Al3(SO4,AsO4)2(OH)6
Hydrated Hydrogen Calcium Aluminum Arsenate Sulfate Hydroxide
Molecular Weight: 463.69 gm
Composition: 
Calcium 2.16 % Ca 3.02 % CaO
Aluminum 17.46 % Al 32.98 % Al2O3
Arsenic 24.24 % As 37.18 % As2O5
Hydrogen 1.79 % H 16.03 % H2O
Sulfur 3.46 % S 8.63 % SO3
Oxygen 50.89 % O
  100.00 % 100.00 % = TOTAL OXIDE
 

 

Crystallography: Trigonal – Hexagonal Scalenohedral
Crystal Habit: As polycrystalline aggregates and crusts.
Twinning: None

 

Cleavage: n/a
Fracture: n/a
Tenacity: Brittle
Moh’s Hardness: 3.0 – 4.0
Density: 1.757 (g/cm3)
Luminescence: None
Radioactivity: Not Radioactive

 

Color: Gray Green, pale Green
Transparency: Translucent to Opaque
Luster: Vitreous to Waxy
Refractive Index: 1.597  Uniaxial ( + )
Birefringence: 0.000
Dispersion: None
Pleochroism: None