| Chemical Classification | Native element – Carbon |
| Color | Most diamonds are brown or yellow in color. The jewelry industry has favored colorless diamonds or those that have a color so subtle that it is difficult to notice. Diamonds in vivid hues of red, orange, green, blue, pink, purple, violet, and yellow are extremely rare and sell for high prices. A few white, gray and black diamonds are also cut and used as gems. Most industrial-grade diamonds are brown, yellow, gray, green and black crystals that lack the color and clarity to be a nice gem. |
| Streak | Diamond is harder than a streak plate. Its streak is known as “none” or “colorless” |
| Luster | Adamantine – the highest level of luster for a nonmetallic mineral. |
| Diaphaneity | Transparent, translucent, opaque. |
| Cleavage | Perfect octahedral cleavage in four directions. |
| Mohs Hardness | 10. Diamond is the hardest-known mineral. However, the hardness of diamond is directional. It is hardest parallel to its octahedral planes and softest parallel to its cubic planes. |
| Specific Gravity | 3.4 to 3.6 |
| Diagnostic Properties | Hardness, heat conductivity, crystal form, index of refraction, specific gravity and dispersion. |
| Chemical Composition | C (elemental carbon) |
| Crystal System | Isometric |
| Uses | Gemstones, industrial abrasives, diamond windows, speaker domes, heat sinks, low-friction microbearings, wear-resistant parts, dies for wire manufacturing. |