Petrographic Data File
| Diopside |
||
|---|---|---|
| Property |
Value |
Comments |
| Formula |
CaMgSi2O6 |
. |
| Crystal System |
Monoclinic |
2/m |
Crystal Habit |
Short, stubby, prismatic crystals with square, rectangular, or eight sided cross section |
. |
| Cleavage |
Fair to good cleavage on (110) Partings on (100) and (001) |
Imperfect cleavage intersecting at 87º and 93º |
Color/Pleochroism |
White to light green |
. |
| Optic Sign |
Biaxial (+) |
|
| 2V |
25-70º |
. |
| Optic
Orientation |
X^a = -20º to -33º, Y = b, Z^c = +35º to +48º |
. |
| Refractive
Indices alpha
=
beta = gamma = delta = |
1.664-1.745 1.672-1.753 1.694-1.771 0.018-0.034 |
. |
| Max
Birefringence |
0.018-0.034 |
|
| Elongation | parallel to c axis | |
| Extinction |
inclined in (010) sections | . |
| Dispersion |
r > v |
- weak to strong |
| Distinguishing
Features |
light green color, cleavage | |
| Occurrence |
Commonly found in metamorphosed carbonate rocks like skarns and marbles. Found with: tremolite, actinolite, grossular garnet, epidote, wollastonite, forsterite, calcite and dolomite |
|
| Editors |
Ruth Indrick ('08) | |
| References |
Nesse, 2000; Blackburn and Dennen, 1988; Klein and Hurlbut, 1977 | |
 |
Diopside is the pale green mineral in the center that has high birefringence and appears second order pink when viewed under crossed polars. The reddish isotropic mineral, found at the top right corner and the top left, is garnet. The clear mineral on the left hand side that appears yellow under crossed polars is wollastonite. |