Vesuvianite crystal structure
tetragonal Nesosilicates

Vesuvianite

Ca19(Al,Mg)13(SiO4)10(Si2O7)4(OH,F)10

Quick Facts

Hardness
6.5
Specific Gravity
3.32
Refractive Index
1.7
Optical Character
Uniaxial - (occasionally +)

Crystal Structure

#! Species: Vesuvianite (Idocrase) #! System: Tetragonal (4/mmm) #! Habit: Prismatic with pinacoid tetragonal[4/mmm]:{100}@1.0 + {110}@0.8 + {001}@0.6
tetragonal
4/mmm
{100} {110} {001}

Physical Properties

Crystal Systemtetragonal
Hardness (Mohs)6.5
Specific Gravity3.32
CleavagePoor {110}
FractureSubconchoidal to uneven
LustreVitreous to resinous

Optical Properties

Refractive Index1.7
Birefringence0.001-0.025
Optical CharacterUniaxial - (occasionally +)
Dispersion0.019
PleochroismWeak

Colours

Green (most common)Yellow-greenYellow-brownBrownBlue (cyprine - copper-bearing)Violet

Localities

Italy (Mount Vesuvius - type locality)Canada (Quebec, British Columbia)Russia (Ural Mountains)USA (California)KenyaPakistan

Common Inclusions

Colour zoningCrystal inclusions

Crystal Forms

tetragonal_prismpinacoid

Notes

Named by Werner in 1795 for crystals from Mount Vesuvius; gemologists often use the older name idocrase

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#! Species: Vesuvianite (Idocrase) #! System: Tetragonal (4/mmm) #! Habit: Prismatic with pinacoid tetragonal[4/mmm]:{100}@1.0 + {110}@0.8 + {001}@0.6