Demantoid
Variety Ca3Fe2(SiO4)3
About it
Green andradite garnet with more fire than diamond. Russian stones from the Ural Mountains often hold curving "horsetail" fibres; Namibia and Madagascar also produce it.
- Type
- Variety
- Group
- Andradite variety (garnet)
- Formula
- Ca3Fe2(SiO4)3
- Hardness (Mohs)
- 6.5–7
- Specific gravity
- 3.8–3.9
- Streak
- white
- Lustre
- adamantine (diamond-like), vitreous (glassy)
- Crystal system
- Isometric (cubic)
- Colours
- yellowish green, emerald green
- Transparency
- transparent
- Cleavage and fracture
- none; conchoidal to uneven fracture
Typical values: real specimens vary. For more, see mindat.org.