Carat Weight Calculator
Estimate a gemstone's carat weight from its dimensions. Enter length, width, and depth in millimeters.
Specific Gravity Reference
Heavier gems (higher SG) will weigh more per unit volume than lighter gems.
| Gemstone | Specific Gravity |
|---|---|
| Zircon | 4.65 |
| Ruby | 4 |
| Sapphire | 4 |
| Garnet | 3.85 |
| Alexandrite | 3.73 |
| Chrysoberyl | 3.73 |
| Tsavorite | 3.61 |
| Spinel | 3.6 |
| Topaz | 3.53 |
| Diamond | 3.52 |
| Tanzanite | 3.35 |
| Peridot | 3.34 |
| Kunzite | 3.18 |
| Tourmaline | 3.06 |
| Paraiba Tourmaline | 3.06 |
| Morganite | 2.85 |
| Turquoise | 2.75 |
| Lapis Lazuli | 2.75 |
| Emerald | 2.72 |
| Aquamarine | 2.72 |
| Pearl | 2.72 |
| Amethyst | 2.65 |
| Citrine | 2.65 |
| Moonstone | 2.57 |
| Opal | 2.15 |