hexagonal Phosphates
Apatite
Ca5(PO4)3(F,Cl,OH)
Quick Facts
Hardness
5.0
Specific Gravity
3.16
Refractive Index
1.628
Optical Character
Uniaxial -
Crystal Structure
#! Species: Apatite
#! System: Hexagonal (6/mmm)
#! Habit: Hexagonal prism with dipyramid and pinacoid
hexagonal[6/mmm]:{10-10}@1.0 + {10-11}@0.8 + {0001}@0.5
hexagonal
6/mmm
{10-10} {10-11} {0001}
Physical Properties
Crystal Systemhexagonal
Hardness (Mohs)5.0
Specific Gravity3.16
CleavagePoor {0001}
FractureConchoidal to uneven
LustreVitreous to subresinous
Optical Properties
Refractive Index1.628
Birefringence0.002-0.008
Optical CharacterUniaxial -
Dispersion0.013
Pleochroismweak: Body color / Lighter/paler shade (Best seen in blue and green varieties; neon blue shows blue/colorless)
FluorescenceVariable; yellow, orange, or blue depending on activator
Colours
Blue (neon, Paraiba-like)GreenYellowVioletPinkColourless
Localities
Brazil (Paraiba blue-green)Madagascar (neon blue)Mexico (yellow)Morocco (tabular)MyanmarTanzania
Common Inclusions
Liquid-filled tubesHealed fracturesCrystals
Known Treatments
Heat treatment (improves colour)
Crystal Forms
hexagonal_prismdipyramidpinacoid
Diagnostic Features
Hexagonal crystals; moderate hardness (5); wide range of fluorescence colours
Notes
Called the deceiver stone because its colours and properties mimic tourmaline, topaz, and other gems
Interactive Preview
Open this crystal in the CDL Playground to rotate, export, and explore in 3D.
Open in Playground #! Species: Apatite
#! System: Hexagonal (6/mmm)
#! Habit: Hexagonal prism with dipyramid and pinacoid
hexagonal[6/mmm]:{10-10}@1.0 + {10-11}@0.8 + {0001}@0.5
Related Minerals
Other minerals in the hexagonal system
