Turquoise
Species
Uncommon · CuAl₆(PO₄)₄(OH)₈·4H₂O
A hydrated copper aluminium phosphate formed in dry, barren regions where acidic, copper-rich groundwater seeps down and reacts with minerals holding phosphorus and aluminium. Copper makes it blue; iron taking the place of aluminium turns it green.
Identity
- Formula
- CuAl₆(PO₄)₄(OH)₈·4H₂O
- Chemical class
- Phosphate
- Also known as
- Turkish stone (archaic), Callais (archaic)
- Used in alchemy
- Turquoise Powder
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
- Granite, Limestone and chalk
- Associated minerals
- kaolinite, montmorillonite, Wavellite, Pyrite
- Geography
- Iran, USA (Arizona, Nevada, New Mexico), China, Mexico, Chile
Classification
- Rarity
- Uncommon
- Gem quality
- Yes
Arcane properties
- Affinity
- Air, Water
- Effects
- Warding, Mind
- Planar origin
- Material Plane
Sources
- M. Pasero and others, IMA Commission on New Minerals, Nomenclature and Classification, The New IMA List of Minerals, updated September 2026. International Mineralogical Association (CNMNC), 2026.
- Turquoise. Mindat.org (Hudson Institute of Mineralogy).
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Turquoise. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- Turquoise. Gemdat.org (Hudson Institute of Mineralogy).
- Turquoise Description. Gemological Institute of America, Gem Encyclopedia.
- Turquoise History and Lore. Gemological Institute of America, Gem Encyclopedia.
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