Blue diamond
| Blue Diamond | |
|---|---|
Closeup of the Hope Diamond, a famous dark blue diamond | |
| General | |
| Category | Native minerals |
| Formula | C B (trace) |
| Strunz classification | 1.CB.10a |
| Crystal system | Cubic |
| Crystal class | Hexoctahedral (m3m) H-M symbol: (4/m 3 2/m) |
| Identification | |
| Formula mass | 12.01 g/mol |
| Color | Light Blue to Deep Blue |
| Crystal habit | Octahedral |
| Twinning | Spinel law common (yielding "macle") |
| Cleavage | 111 (perfect in four directions) |
| Fracture | Conchoidal (shell-like) |
| Mohs scale hardness | 10 (defining mineral) |
| Luster | Adamantine |
| Streak | Colorless |
| Diaphaneity | Transparent to subtransparent to translucent |
| Specific gravity | 3.52±0.01 |
| Density | 3.5–3.53 g/cm3 |
| Polish luster | Adamantine |
| Optical properties | Isotropic |
| Refractive index | 2.418 (at 500 nm) |
| Birefringence | None |
| Pleochroism | None |
| Dispersion | 0.044 |
| Melting point | Pressure dependent |
| References | |
Blue diamonds are a type of diamond which exhibit all of the same inherent properties of the mineral except with the additional element of blue color in the stone. The Mohs hardness of a blue diamond is around the same as a regular diamond, with a hardness of 10. They are colored blue by trace impurities of boron within the crystalline lattice structure. Blue diamonds belong to a subcategory of diamonds called fancy color diamonds, the generic name for diamonds that exhibit intense color.