Jadeite
JadeiteJewelryWiki Editorial·4 sources·Reviewed 2026-08-04
One of the two minerals sold as jade. Moderate hardness but exceptional toughness from its interlocking crystal structure — the classic case of the two axes diverging.
Properties
| Property | Value | Authority |
|---|---|---|
| Mohs hardness | 6½–7 [1] | — |
| Refractive index | 1.652–1.688 [1] | — |
| Specific gravity | 3.30–3.38 [1] | — |
| Chemical formula | Na(Al,Fe3+)Si2O6 [4] | — |
| Crystal system | Monoclinic [2] | — |
| Common treatments | Commonly bleached and then impregnated, as a two-step process rather than one. Acid bleaching removes an unwanted brown component, but leaves the material slightly porous and vulnerable to breaking along fractures, so it is then impregnated with polymer to fill those spaces. GIA records bleaching as frequently encountered in jadeite. The bleaching step alone is virtually impossible to detect; the impregnation is easier for a laboratory to find. [3] | — |
| Care cautions | Polymer impregnation is damaged by heat — keep the piece away from a jeweller’s torch — and by chemicals. [3] | — |
Sources
- International Gem Society — reference charts (Mohs hardness, specific gravity, refractive index) — International Gem Society (IGS reference charts)
- Wikipedia — mineral article infoboxes (crystal system) — Wikipedia contributors (Wikipedia mineral infoboxes)
- GIA — An Introduction to Gem Treatments — Gemological Institute of America (GIA, An Introduction to Gem Treatments (Robert Weldon))
- Handbook of Mineralogy — Mineral Data Publishing / Mineralogical Society of America (Handbook of Mineralogy, Mineral Data Publishing)