Amazonite
Microcline feldsparJewelryWiki Editorial·4 sources·Reviewed 2026-08-04
The blue-green microcline. Named for the Amazon river despite no confirmed deposit there — a naming error that stuck.
Properties
| Property | Value | Authority |
|---|---|---|
| Mohs hardness | 6–6½ [1] | — |
| Refractive index | 1.522–1.530 [1] | — |
| Specific gravity | 2.56–2.58 [1] | — |
| Chemical formula | KAlSi3O8 Read from the species entry, Microcline. A variety shares its species’ formula — unlike hardness or density, which vary with composition and are not inherited here. [4] | — |
| Crystal system | Triclinic [2] Read from the species article, Microcline. | — |
| Common treatments | Among the opaque gems GIA names as impregnated with wax or plastic to improve durability and appearance. Impregnation is frequently seen in the trade and is often only skin deep. [3] | — |
| Care cautions | Keep away from heat — a jeweller’s torch will likely damage a wax or plastic impregnation. [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)