Spessartine
Species
Uncommon · Mn₃Al₂(SiO₄)₃
Manganese aluminium garnet ranging from orange to red-brown in colour. Forms in granites, pegmatites, and metamorphic rocks rich in manganese. The vivid orange stones sold as mandarin garnet, from Namibia and Nigeria, are particularly prized.
Identity
- Formula
- Mn₃Al₂(SiO₄)₃
- Chemical class
- Silicate
- Part of
- Garnet
- Mineral group
- Demantoid, Garnet, Grossular, Tsavorite, Uvarovite
- Also known as
- Spessartite, Mandarin garnet (orange variety)
Crystallography
- Crystal system
- Cubic
- Habits
- Dodecahedral, Massive
- Fracture
- Conchoidal
Physical properties
- Mohs hardness
- 7.5
- Density
- 4.18 g/cm³
- Luster
- Vitreous
- Colors
- orange, red, yellow, orange-red
- Streak
- white
- Transparency
- Transparent, Translucent
Geology
- Origins
- Metamorphic, Igneous
- Host rocks
- Granite, Volcanic rock, Marble
- Associated minerals
- Quartz, Mica, Tourmaline
- Found in
- Pegmatite deposit, Skarn
- Geography
- Nigeria, Brazil, USA, Germany, Tanzania
Classification
- Rarity
- Uncommon
- Gem quality
- Yes
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.
- Spessartine. Mindat.org (Hudson Institute of Mineralogy).
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Spessartine. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- Spessartine. Gemdat.org (Hudson Institute of Mineralogy).
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