Transparent, gem-quality magnesite is rare and beautiful, with colors ranging from colorless, white, and gray to a yellowish brown. This material is relatively difficult to cut, so faceted stones are rarely seen. Cabochons are more common.
After the magnesium (Mg) in its composition.
Alteration product of magnesium-rich rocks; sedimentary deposits; as a gangue mineral in hydrothermal ore deposits.
Magnesite accepts dye treatments very well due to its porousness. Since cabochon or bead shapes are common, dyed specimens are sometimes sold as turquoise. If the material is disclosed as treated or a turquoise simulant, this is an acceptable practice. If not, buyer beware.
Facetable crystals come only from Brazil. Brumado, Bahia produces large, magnificent rhomb-shaped crystals, often transparent and colorless.
Other notable crystal sources include the following:
Algeria; Austria, India; Korea; Norway; South Africa; Zaire.
The Smithsonian Institution holds the largest known cut magnesite, a 390-carat cushion-step gem from Brazilian material. However, most gem-quality material occurs in sizes under 10-15 carats.
Due to magnesite’s very low hardness, gems and jewelry made from this material should be stored in a cloth bag or box, away from other gems. Harder gems could scratch them. (A knife could scratch the surface of most of these stones). Consult our gemstone jewelry cleaning guide for more care recommendations.