Spessartine

History

The name spessartine points to a low range of forested hills in central Germany — the Spessart Mountains — where the mineral was first found.

The earliest description came from the German chemist Martin Klaproth in 1797. Working on a specimen from the Spessart range, he gave it the cumbersome German label granatförmiges Braunsteinerz — literally "garnet-shaped brownstone ore". The name captured two things at once: the crystal habit of a garnet, and the manganese content that gives the mineral its colour. Braunstein — brownstone — was the German term of the day for manganese ore.

A clearer chemical identity arrived in 1823. The American chemist Henry Seybert examined a specimen from Haddam, Connecticut, and recognised it as a manganese-bearing member of the garnet family — a "manganesian" garnet in the language of the period.

The modern name was coined nine years later. In 1832 the French mineralogist François Sulpice Beudant renamed the species spessartine, after the Spessart type locality where Klaproth's specimen had come from.

For more than a century afterwards, spessartine remained a curiosity for mineralogists and a quiet name in collector cabinets. That changed in 1991, when prospectors working the bush country along the Kunene River in northwestern Namibia uncovered an iron-free, brilliant orange variety embedded in mica schist — fine-grained metamorphic rock made largely of mica flakes. Marketed under several short-lived names — including hollandine and Kunene spessartine — the stone settled in the trade as mandarin garnet. A second deposit surfaced in southwestern Nigeria in April 1994, in a riverbed near the border with Benin.

Industrial & practical applications

Spessartine's role today is almost entirely as a gemstone. When the crystal is clear, it cuts a semiprecious stone, prized above all for the saturated orange variety the trade calls mandarin garnet.

That orange variety — iron-free and almost luminous in colour — is the version most jewellers and collectors actually pursue. Top-quality stones are extremely rare, and the supply moves with whichever deposit happens to be producing. The principal modern sources are pegmatite-hosted finds in Madagascar, the 1991 Kunene-River occurrence in northwestern Namibia, and the southwestern Nigerian riverbed discovered in 1994. Violet-red spessartines turn up in the volcanic rhyolites of Colorado and Maine, and pale yellow-orange to deep red material has long been collected from granites and pegmatites in central India, Madagascar, and Silver Cliff, Colorado.

Beyond the gem trade, spessartine has no significant industrial role. The mineral is rare enough that, even within jewellery, it sees less use than other members of the garnet family. Its value rests almost entirely on its colour.

Where it forms, where it's found

Type locality: Spessartine occurrence
Stengerts
Gailbach
Aschaffenburg
Lower Franconia
Bavaria
Germany
49.9447°, 9.1961°

1,151recorded occurrences

Source · OpenStreetMap

Varieties

Brandãosite(Mn,Fe)₄(Al,Fe)₂Si₄O₁₅
Variety
—

Physical

Hardness: 1Talc
2Gypsum
3Calcite
4Fluorite
5Apatite
6Orthoclase
7Quartz
8Topaz
9Corundum
10Diamond
Lustre: Vitreous - Resinous
Transparency: Transparent · Translucent
Colour: Red · reddish orange · yellowish brown · reddish brown · or brown
The “alexandrite effect” is when its colour changes from green in the presence of daylight to purplish red under incandescent light. The UV-Vis spectra show two zones of transmittance, in the red region at 650–700 nm and the blue-green region at 460–510 nm. The absorption bands of Cr³⁺ and V3⁺ at 574 nm in the UV-Vis spectra are the main cause of the change in colour.[[2]] <br><br> There are transition metal elements in garnet, and the main theory of its color formation is crystal field theory. Fe2+ and Mn2+ are the main color-causing ions in purple pyrope–almandines, for Mg2+ is insignificant for the color of the samples. As an island silicate mineral, peridot’s beautiful color is also caused by Fe2+. However, it is worth noting that the almandine–skiagite’s brownish yellow color is caused by the charge transfer between element ions. Spessartine’s color is vivid orange. There are many research studies on the color causes and spectrum about spessartines; we find that the reason why spessartines appear a beautiful orange is not only the Mn2+ d-d electron transition, but also the valence charge transfer transition between Fe2+and Fe3+. They obviously absorb in the area of the blue-purple region, which makes the spessartines appear a bright color. As one of the most promising colored gemstones on the market, spessartine is becoming increasingly popular. According to the CIE 1976 L*a*b*, the relationship between chroma C*, the h° and colorate coordinates a* and b* was analyzed. The chemical composition was analyzed according to ED-XRF, then we quantitatively analyzed the impact of the elements FeOtot and MnO and the ratio FeOtot/MnO on color parameters L*, h°. By analyzing the UV-visible spectrum of spessartines, we find the color mechanism of the samples. It is worth noting that this article is the first to studied the relationship between the peaks’ position in the infrared spectrum and the color parameters of spessartines. With the increase in MnO content, the A, C and D peaks in the infrared spectrum shifted from the region of high frequency to low frequency, the color parameters L* and h° both increased, and the spessartines’ color also changed from dark orange-red to bright orange. [[1]]
Streak: White
Tenacity: brittle
Cleavage: Distinct
Fracture: Sub-Conchoidal
Density: 4.12 g/cm³

Optical

Optical type: Isotropic
Surface relief: Very high
Principal indices: n 1.800
Luminescence: Non-fluorescent

Isotropy testPPL ↔ XPL diagnostic

PPL intrinsic colour; no change on stage rotation

XPL extinct at every orientation

Single index: n = 1.800

Crystallography

Crystal system: Isometric
Space group: Ia3d
Cell parameters: a = 11.621 Å
Z: 8
Morphology: euhedral crystals, dodecahedra or trapezohedra, or in combination with other cubic forms, to 10 cm.

Crystal structure

Chemical composition

Constituent elements: Mass composition breakdown
Element Atoms At. mass g/mol Mass g/mol Mass share
8OOxygen Oxygen 12 15.999 191.988
38.78%
25MnManganese Manganese 3 54.938 164.814
33.30%
14SiSilicon Silicon 3 28.085 84.255
17.02%
13AlAluminium Aluminium 2 26.982 53.964
10.90%
Total 495.021 100.00%
Mass share = atoms × atomic mass ÷ molar mass × 100
From IMA formula
Impurities: Ti
Fe
Mg
Ca
H2O
Y

Mass composition breakdown
Element	Atoms	At. mass g/mol	Mass g/mol	Mass share
8OOxygen	Oxygen	12	15.999	191.988	38.78%
25MnManganese	Manganese	3	54.938	164.814	33.30%
14SiSilicon	Silicon	3	28.085	84.255	17.02%
13AlAluminium	Aluminium	2	26.982	53.964	10.90%
	Total	495.021	100.00%

Synonyms

Erinite (of van der Lingen)
Kashmirine
Mandarin Garnet
Mandarin Granat
Partschinite
Spessartine Garnet
Spessartit
Spessartite
Spessartite garnet

In other languages

French: spessartine
German: Spessartin
Spanish: Espesartina · Spessartina
Italian: spessartina
Japanese: 満礬柘榴石
Chinese: 巴西錳鋁石榴石 · 鈣錳鋁榴石 · 錳鋁榴石
Russian: спессартин
Arabic: سبيسارتين

Classification

Strunz

10th ed.

9.AD.25

9SilicatesClass
9.ANesosilicatesDivision
9.ADNesosilicates without additional anions; cations in [6] and/or greater coordinationGroup
9.AD.25SpessartineSpecies

Dana

8th ed.

51.04.3a.03

51Nesosilicates Insular Sio₄ Groups OnlyClass
51.04Insular SiO₄ Groups Only with cations in [6] and >[6] coordinationType
51.04.3a— unnamed intermediate level —Group
51.04.3a.03SpessartineSpecies

CIM

—

16.16.2

16Silicates Containing Aluminum and other MetalsClass
16.16Aluminosilicates of MnGroup
16.16.2SpessartineSpecies

Group, growth & confusion

14 members

6 minerals

Literature, links & citation

Citations

1883Gorgeu, Alex. (1883) Sur la production artificielle de la Spessartine. Bulletin de Minéralogie, 6 (8) 283-284 doi:10.3406/bulmi.1883.1829DOI: 10.3406/bulmi.1883.1829
1959Geller, S., Miller, C. E. (1959) Substitution of Fe3+ for Al3+ in synthetic spessartite. American Mineralogist, 44 (5-6) 665-666
1971Novak, G. A., Gibbs, G. V. (1971) The crystal chemistry of the silicate garnets. American Mineralogist, 56 (5-6) 791-825
1988Rossman, G.R., Rauch, F., Livi, R., Tombrello, T.A., Shi, C.R., Zhoi, Z.Y. (1988) Nuclear reaction analysis of hydrogen in almandine, pyrope and spessartine garnets. Neues Jahrbuch für Mineralogie Monatshefte: 4: 172-178.
1990Smyth, Joseph R., Madel, Robin E., Mccormick, Tamsin C., Munoz, James L., Rossman, George R. (1990) Crystal structure refinement of a F-bearing spessartine garnet. American Mineralogist, 75 (3-4) 314-318

Cite this entry

@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Spessartine — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/spessartine-3725},
  note      = {Accessed 2026-05-11}
}