Demantoid
Varietyof Andradite
Demantoid is the green gem variety of andradite garnet. As a variety of Andradite, it shares that species' composition (Ca3Fe3+2(SiO4)3), crystal structure, and hardness; the distinction is the appearance defined above.
Photos
About Andradite
Full reference data — crystallography, X-ray diffraction, and cited physical properties — is on the Andradite species page.
| Formula | Ca3Fe3+2(SiO4)3 |
|---|---|
| Specific gravity | 4.25 |
| Density (calculated) | 3.845 |
| Crystal system | cubic |
| Color range | black, brown, red |
| Streak | white |