monoclinic Inosilicates

Diopside

Formula CaMgSi2O6

Crystal Structure

CDL Notation

 #! Species: Diopside
#! System: Monoclinic (2/m)
#! Habit: Short prismatic with well-developed pinacoid
monoclinic[2/m]:{110}@1.0 + {100}@0.6 + {010}@0.5 + {001}@0.9

Crystal System monoclinic

Point Group 2/m

Crystal Forms (4)

{110} {100} {010} {001}

Quick Facts

Hardness

5.5

Specific Gravity

3.22

Refractive Index

1.675

Optical Character

Biaxial +

Physical Properties

Crystal System: monoclinic
Hardness (Mohs): 5.5
Specific Gravity: 3.22
Cleavage: Good {110} at 87-93 degrees (characteristic pyroxene cleavage)
Fracture: Uneven to conchoidal
Lustre: Vitreous

Optical Properties

Refractive Index: 1.675
Birefringence: 0.024-0.030
Optical Character: Biaxial +
Dispersion: 0.02
Pleochroism: moderate: Light green / Dark green (Strong in chrome diopside; weak in other varieties)
Fluorescence: Strong blue to bluish-white (SWUV)