The definition "jade" is used to define two minerals of similar appearance but different chemical composition: nephrite, a calcium- magnesium silicate, and jadeite, a silicate of sodium and aluminum.
Both minerals are found in a wide range of shades of green, brown, yellow, grey and pink and may be either translucent or opaque. They may be milky or cloudy in appearance and sometimes speckled with tiny black spots.
The most prized of the jades, the so-called "Chinese jade" (jadeite) is emerald green and so beautiful and rare that it has become exorbitantly expensive. In fact, jade is a good investment only if purchased at a reasonable price. A sound policy is never pay more for Chinese jade than you would for an emerald.
| Name | Moh's | Specific Gravity | Structure | Cleavage | Refractive Index | Double | Disp. | Pleochro | Fluorescence |
| Chloromelanite Jade | 6.5+ | 3.30-3.36 | Monoclinic | Imperfect | 1.654-1.667 | 0.013 to None | None | None | v Weak |
| Jadeite Jade | 6.5+ | 3.35 | Monoclinic | Imperfect | 1.654-1.667 | 0.013 to None | None | None | v Weak |
| Nephrite Jade | 6+ | 2.90-3.02 | Monoclinic | Lengthwise: perfect | 1.600-1.627 | -0.027 to none | None | Weak | None |