amorphous Phosphates
Turquoise (Massive (typical))
CuAl6(PO4)4(OH)8.4H2O
Quick Facts
Hardness
5.0
Specific Gravity
2.6
Refractive Index
1.61
Optical Character
Biaxial +
Crystal Structure
#! Species: Turquoise
#! System: Amorphous (cryptocrystalline)
#! Habit: Massive and nodular aggregates
amorphous[cryptocrystalline]:{massive, nodular}[colour:blue]
amorphous
-1
{massive, nodular}
Physical Properties
Crystal Systemamorphous
Hardness (Mohs)5.0
Specific Gravity2.6
CleavageGood {001}, poor {010}
FractureConchoidal to smooth
LustreWaxy to sub-vitreous
Optical Properties
Refractive Index1.61
Birefringence0.04
Optical CharacterBiaxial +
PleochroismNone (typically aggregate)
Colours
Sky blue (Persian blue - most valued)Blue-greenGreenish-blueApple greenWith matrix patterns
Localities
Iran (Nishapur - finest Persian blue)USA (Arizona, Nevada, New Mexico)Egypt (Sinai - historic)China (Hubei)TibetMexico
Known Treatments
Stabilization (most material)Wax/oil impregnationZachery processDyeingReconstitution
Crystal Forms
massivenodularveins
Notes
Most commercial turquoise is stabilized; untreated gem-quality material commands premium prices
Interactive Preview
Open this crystal in the CDL Playground to rotate, export, and explore in 3D.
Open in Playground #! Species: Turquoise
#! System: Amorphous (cryptocrystalline)
#! Habit: Massive and nodular aggregates
amorphous[cryptocrystalline]:{massive, nodular}[colour:blue]
Synthetics & Simulants
Known synthetic and simulant versions of Turquoise (Massive (typical))
Related Minerals
Other minerals in the amorphous system
