Test with rare-earth magnet (N42 or N52 neodymium). Suspend specimen on thread for sensitive paramagnetic detection. Diamagnetic minerals are weakly repelled (visible only with strong magnets like bismuth).
Specific Gravity
4.12–4.32
g/cm³
heavy
Mn-Al garnet; orange "mandarin".
For comparison: water = 1.00, glass ≈ 2.5, quartz = 2.65, corundum ≈ 4.00, galena ≈ 7.50, gold ≈ 19.3.
🟡
Market availability: Uncommon
Found at major shows and select dealers. Quality varies by locality.
Mohs6.5–7.5
Vickers (~)1400 HV
Knoop (~)1100 HK
Geological setting
💎Pegmatite
Element composition by mass
Formula: Mn₃Al₂(SiO₄)₃ · molar mass: 495.02 g/mol
O
38.78%
Mn
33.29%
Si
17.02%
Al
10.9%
Computed from atomic weights (IUPAC 2021). Site-occupancy groups (Fe,Mn) split equally.
Spessartine sits at 6.5–7.5 on the Mohs scale —
harder than glass; scratches steel.
Colors:
Streak White
Crystal system Isometric (Cubic)
Discovery First described 1832 by François Sulpice Beudant (Bavaria)
SilicatesSilicates (Nesosilicates)
TL;DR · 1 min read
Spessartine (Mn₃Al₂(SiO₄)₃) is the manganese end-member of the garnet group, completing the pyralspite trio with almandine (Fe) and pyrope (Mg). Its signature is a vivid orange-to-red gem color from manganese, often described as "mandarin orange.
Spessartine (Mn₃Al₂(SiO₄)₃) is the manganese end-member of the garnet group, completing the pyralspite trio with almandine (Fe) and pyrope (Mg). Its signature is a vivid orange-to-red gem color from manganese, often described as “mandarin orange.” China hosts globally significant gem-quality Spessartine localities at Tongbei (Fujian) and several Yunnan deposits, where transparent dodecahedral crystals are mined for both faceted gem material and prized matrix specimens.
MyMineralBox Editorial Team. (2026). Spessartine. My Mineral Box. Retrieved May 23, 2026, from https://mymineralbox.com/mineral-encyclopedia/minerals/spessartine/
MLA
MyMineralBox Editorial Team. "Spessartine." My Mineral Box, 2026, https://mymineralbox.com/mineral-encyclopedia/minerals/spessartine/. Accessed May 23, 2026.
Chicago
MyMineralBox Editorial Team. "Spessartine." My Mineral Box. Last modified May 5, 2026. https://mymineralbox.com/mineral-encyclopedia/minerals/spessartine/.
BibTeX
@misc{mmb_spessartine,
author = {{MyMineralBox Editorial Team}},
title = {{Spessartine}},
year = {2026},
publisher = {My Mineral Box},
url = {https://mymineralbox.com/mineral-encyclopedia/minerals/spessartine/},
urldate = {2026-05-23}
}
About Spessartine
Spessartine is a silicate mineral in the garnet supergroup / garnet group and has the chemical formula Mn²⁺₃Al₂(SiO₄)₃. It crystallizes in the isometric system and ranks among the harder species, with lasting durability. Its combination of structural character and global distribution make it a recognized species in both systematic and aesthetic collections.
Identification & care
Spessartine typically forms dodecahedral, trapezohedral; massive. Its color is typically orange to orange-red, reddish-orange and yellow-orange. The luster is vitreous, resinous, the streak is white, and specimens range from transparent to translucent. The fracture is conchoidal to uneven, which is one of its key identifying features.
Collector context
How it forms
In terms of geology, Spessartine forms in granitic pegmatites; metamorphic rocks. It is commonly found in association with quartz, feldspar, tourmaline, columbite.
Classic Chinese localities
Documented Chinese occurrences are recorded at Jiama Cu-polymetallic deposit, Dachang ore field and Huanggang Fe-Sn deposit, among others.
Why collectors care
Collectors pursue Spessartine for the clarity of its crystal form and, in good material, saturated color that reads instantly across a display case. A well-terminated spessartine on clean matrix photographs well, identifies quickly, and anchors a cabinet piece. Top Chinese specimens over the last two decades have reset the bar for what spessartine looks like at collector grade.
What affects value
Value in Spessartine is assessed, in typical order of weight, against: (1) locality provenance; (2) size relative to the species norm; (3) crystal form and termination sharpness; (4) color saturation and zoning; (5) transparency and internal clarity; (6) matrix quality and aesthetic balance; (7) condition (absence of damage, chips, or repair). Cleaning quality and verified locality documentation act as multipliers across the above.
Naming history
The name Spessartine has a specific etymological and historical context — see Mindat's reference entry for provenance details. We have retained naming data at the record level; published prose is paraphrased from factual fields rather than copied from source.
Frequently asked questions
What is Spessartine?
Spessartine is a silicate mineral recognized for its hardness and durability, with several world-class Chinese localities.
What is the chemical formula of Spessartine?
The chemical formula of Spessartine is Mn3Al2(SiO4)3.
What crystal system does Spessartine belong to?
Spessartine crystallises in the Isometric crystal system.
Is Spessartine rare?
As a collector mineral, Spessartine is generally considered uncommon.
Mindat.org is the world’s largest open mineralogy database. Our descriptions are written independently and fact-checked.
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