Turquoise
Image: Robert M. Lavinsky (CC BY-SA 3.0)
Mineral NameTurquoise
Chemical FormulaCuAl₆(PO₄)₄(OH)₈·4H₂O
Mohs Hardness5
Crystal Systemtriclinic
Lusterwaxy
Streak Colorwhite to pale blue/green
Cleavagepoor to none
Fractureconchoidal
Specific Gravity2.7
Colorsblue, blue-green, green
Transparencyopaque
Type LocalityMount Kourou Diakouma (Kouroudiako), Saraya, Falémé River basin, Tambacounda Region
Mineral GroupPhosphates
Usesjewelry, ornamental stone, collector
Associated Mineralssenegalite
Rarityuncommon
Description
This specimen displays turquoise, likely in a massive or cryptocrystalline form, characterized by its distinctive blue-green color. It appears to be associated with another mineral, possibly senegalite, as indicated by the metadata.
Geological Context
Turquoise is a secondary mineral formed by the alteration of aluminum-rich igneous rocks, typically in arid regions. It precipitates from circulating groundwater that has leached copper and aluminum from surrounding rocks.
