Grossular
Mineral Ca3Al2(SiO4)3
Also called Cinnamon stone and Rosolite
About it
Calcium-aluminium garnet of altered limestone, in every colour except blue; orange and pink crystals from Quebec's Jeffrey mine, and green tsavorite from Kenya and Tanzania.
- Type
- Mineral
- Group
- Silicate (nesosilicate), garnet group
- Formula
- Ca3Al2(SiO4)3
- Hardness (Mohs)
- 6.5–7.5
- Specific gravity
- 3.57–3.73
- Streak
- white
- Lustre
- vitreous (glassy), resinous
- Crystal system
- Isometric (cubic)
- Colours
- colourless, white, green, yellow, orange, pink, brown
- Transparency
- transparent, translucent
- Cleavage and fracture
- none; conchoidal to uneven fracture
Typical values: real specimens vary. For more, see mindat.org.