Spessartine
| Spessartine | |
|---|---|
Isotropic, often anomalous double refractive | |
| Refractive index | 1.800 |
| Birefringence | none |
| Dispersion | Weak |
| Absorption spectra | Bands at 410, 420, 430 nm (or merging to form cutoff below 430 nm; also bands at 460, 480, 520 nm. Possible weak bands at 504 or 573 nm[2] |
| References | [3][4][5] |
Spessartine is a
nesosilicate, manganese aluminium garnet species, Mn2+3Al2(SiO4)3.[2][3][4][5] This mineral is sometimes mistakenly referred to as spessartite.[6]
Spessartine's name is a derivative of
orange-yellow has been called Mandarin garnet and is found in Madagascar. Violet-red spessartines are found in rhyolites in Colorado and Maine. In Madagascar, spessartines are exploited either in their bedrock or in alluvium. The orange garnets result from sodium-rich pegmatites. Spessartines are found in bedrock in the highlands in the Sahatany valley. Those in alluvium are generally found in southern Madagascar or in the Maevatanana region.[7][8][9][10][11]
Spessartine forms a solid solution series with the garnet species almandine.[4][5] Well-formed crystals from this series, varying in color from very dark-red to bright yellow-orange, were found in Latinka, Rhodope Mountains, Kardzhali Province, Bulgaria.[12] Spessartine, like the other garnets, always occurs as a blend with other species. Gems with high spessartine content tend toward a light orange hue, while almandine prevalence induces red or brownish hues.[13]
Images
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Spessartine crystal from Pakistan -
Spessartine on smoky quartz: Wushan Spessartine Mine, Tongbei, Fujian Province, China -
Reddish-orange spessartine -
Two "frog-eyes" of 1.8 cm each sit perched atop a matrix
See also
References
- S2CID 235729616.
- ^ ISBN 0-87311-019-6
- ^ a b c d Webmineral Spessartine page
- ^ a b c d e Mindat Spessartine page
- ^ a b c d "Handbook of Mineralogy Spessartine page" (PDF). Archived from the original (PDF) on 2016-03-04. Retrieved 2009-06-06.
- .
- .
- .
- .
- S2CID 140651302.
- .
- ^ "Spessartine from Latinka, Bulgaria".
- ^ Spessartite Garnet Gemological Information
External links
Media related to Spessartine at Wikimedia Commons
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