Magnesite
Species
Common · MgCO₃
Magnesium carbonate, usually white, chalky or porcelain-like, formed by alteration of serpentinite and peridotite. Much of it is burnt to magnesia for the refractory linings of blast furnaces and kilns, and it is also an ore of magnesium; its cupels serve in fire assay. Named for Magnesia in Greece; immense deposits lie in Liaoning, China.
Identity
- Formula
- MgCO₃
- Chemical class
- Carbonate
- Ore of
- Magnesium
Crystallography
- Crystal system
- Trigonal
- Habits
- Rhombohedral, Earthy, Fibrous, Granular, Massive
- Fracture
- Conchoidal
Physical properties
- Mohs hardness
- 4
- Density
- 3 g/cm³
- Luster
- Vitreous, Dull
- Colors
- white, colorless, pale yellow, brown, light pink
- Streak
- white
- Transparency
- Transparent, Translucent
Geology
- Origins
- Metamorphic, Sedimentary
- Host rocks
- Ultramafic rock (peridotite, serpentinite)
- Associated minerals
- Talc, Serpentine, Chlorite, Dolomite, Calcite
- Found in
- Soapstone
- Geography
- China (Liaoning), Austria (Radenthein, Carinthia; Trieben, Styria), Greece (Magnesia), Brazil (Brumado, Bahia), USA (Gabbs, Nevada), Italy (Baldissero Canavese)
Classification
- Rarity
- Common
- Gem quality
- No
Sources
- M. Pasero and others, IMA Commission on New Minerals, Nomenclature and Classification, The New IMA List of Minerals, updated September 2026. International Mineralogical Association (CNMNC), 2026.
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Magnesite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- Magnesite. Wikipedia.
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