TURQUOISE
HARDNESS: 5-6
DENSITY: 2,6 – 2,8 g/cm³
SCRATCH: White
BRIGHTNESS: Transparent, translucent to opaque
EXFOLIATION- FRACTURE: Good - Conchoidal
CRYSTALLIZATION: Triclinic system
TRANSPARENCY: Transparent, translucent to opaque
This semiprecious stone is an aluminum and copper phosphate, which is highly valued for its quality and scarcity. Light blue, bluish green or green, it was already used in Ancient Egypt. The blue color is attributed to copper, while the green color may be the result of iron impurities or dehydration. It is a rare mineral, of secondary formation and is found mainly in desert regions. The mines of the current Iran, Sinai or the United States stand out. In Spain you can find turquoises based on ambligonite in the Valdeflorez mine (Cáceres).