Garnet
Mineral (Ca,Fe,Mg,Mn)3(Al,Fe,Cr)2(SiO4)3
About it
Group name for hard, rounded twelve- or 24-sided crystals with no cleavage, mostly red to brown but also green, orange, and black. Almandine, pyrope, spessartine, grossular, andradite, and uvarovite are listed separately.
- Type
- Mineral
- Group
- Silicate (nesosilicate), garnet group
- Formula
- (Ca,Fe,Mg,Mn)3(Al,Fe,Cr)2(SiO4)3
- Hardness (Mohs)
- 6.5–7.5
- Specific gravity
- 3.5–4.3
- Streak
- white
- Lustre
- vitreous (glassy), resinous
- Crystal system
- Isometric (cubic)
- Colours
- red, brown, orange, green, yellow, black, pink
- Transparency
- transparent, translucent, opaque
- Cleavage and fracture
- none; conchoidal to uneven fracture
Typical values: real specimens vary. For more, see mindat.org.