Turquoise

Real mineral · uncommon · CuAl₆(PO₄)₄(OH)₈·4H₂O

A hydrated copper aluminium phosphate formed in arid regions where copper-bearing groundwater interacts with aluminium-rich rocks. Its colour ranges from sky blue to green depending on iron content.

Identity

Formula
CuAl₆(PO₄)₄(OH)₈·4H₂O
Chemical class
phosphate
Also known as
Turkish stone (archaic), Callais (archaic)

Crystallography

Crystal system
triclinic
Habits
massive, nodular, earthy
Fracture
conchoidal

Physical properties

Mohs hardness
5.5
Density
2.7 g/cm³
Luster
waxy, dull
Colors
sky blue, blue-green, green, pale blue
Streak
white
Transparency
opaque, translucent

Geology

Origins
sedimentary, hydrothermal
Host rocks
limestone, sandstone, porphyry
Associated minerals
Chalcopyrite, Quartz, limonite
Geography
Iran, USA (Arizona, Nevada), Egypt, China, Mexico

Classification

Rarity
uncommon
Gem quality
Yes

Arcane properties

Affinity
air, water
Effects
warding, mind
Planar origin
Material Plane

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