Diopside
Diopside is a mineral known for its pronounced pleochroism (the property where the color appears to change depending on the viewing angle). Due to this characteristic, its name is derived from a word meaning "two appearances." It often contains iron (Fe) as an impurity and generally appears green (pure specimens are colorless).
Diopside, characterized by its pleochroism and green coloration
Basic Information
| English Name | Diopside |
|---|---|
| Japanese Name | 透輝石 (Tokiseki) |
| Chemical Composition | CaMg[Si2O6] |
| Crystal System | Monoclinic |
| Hardness | 5.5–6.5 |
| Specific Gravity | 3.30 |
| Transparency | Transparent to translucent (opaque in some varieties) |
Characteristics & Varieties
- Pleochroism: A major feature is that its color often appears different depending on the viewing angle.
- General Color: Often contains iron (Fe) and is usually green (pure specimens are colorless).
- Violane: A blue-violet variety containing trace amounts of manganese (Mn), discovered in the Piedmont region of Italy in the 18th century.
- Rare Colors: Colorless, emerald green, and deep green.
Varieties
- Chrome Diopside: Contains chromium (Cr), resulting in a vibrant emerald green color.
- Diopside Cat's Eye: Features a distinct line of reflected light due to dense tubular inclusions.
- Star Diopside: Often black and opaque; tends to show a four-rayed star where the lines are slightly slanted and one is often broader.
Origin, Synonyms, Treatments, & Similar Stones
Trade Names: Hidaka Jade (massive diopside found in the Hidaka region of Hokkaido)
Treatments: None notable
Similar Stones:
Note: Because it is a strongly pleochroic stone, its color impression can change significantly based on the viewing angle and lighting conditions. In particular, the appearance of cat's eye and star effects can vary depending on the state of the inclusions and the quality of the cut.