Bort
Variety C
Also called Boart
About it
Diamond too flawed, dark, or poorly crystallized for gems, crushed for grit, saw blades, and drill bits. A large share of all mined diamond is bort.
- Type
- Variety
- Group
- Diamond variety
- Formula
- C
- Hardness (Mohs)
- 10
- Specific gravity
- 3.5–3.53
- Lustre
- adamantine (diamond-like), greasy
- Crystal system
- Isometric (cubic)
- Colours
- grey, brown, black, yellowish
- Transparency
- translucent, opaque
- Cleavage and fracture
- perfect octahedral; conchoidal to splintery fracture
Typical values: real specimens vary. For more, see mindat.org.