- Spessartine
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Spessartine 
Spessartine from ChinaGeneral Category Nesosilicate Chemical formula Mn(II)3Al2(SiO4)3 Strunz classification 09.AD.25 Identification Molar mass 495.03 g Color yellow through red Crystal habit massive to crystalline Crystal system Isometric - Hexoctahedral Fracture sub Conchoidal Tenacity brittle Mohs scale hardness 6.5 - 7.5 Luster vitreous Streak white Diaphaneity transparent to translucent Specific gravity 4.15 (+.05, -.03)[1] Optical properties Isotropic, often anomalous double refractive Refractive index 1.810 (+.004, -.020) Birefringence none Dispersion weak Absorption spectra bands at 410, 420, 430nm (or merging to form cutoff below 430nm; also bands at 460, 480, 520nm. Possible weak bands at 504, or 573nm [1] References [2][3][4] Spessartine previously named spessartite, is a nesosilicate, manganese aluminium garnet species, Mn(II)3Al2(SiO4)3.[2][3][1][4]
The name is a derivative of Spessart in Bavaria, Germany, the type locality of the mineral.[2][3] It occurs most often in granite pegmatite[2][3][4] and allied rock types and in certain low grade metamorphic phyllites. Sources include Australia, Myanmar, India, Afghanistan, Israel, Madagascar, Tanzania and the US.[1] Spessartine of an orange-yellow has been called Mandarin garnet and is found in Madagascar. . Violet-red spessartines are found in rhyolites in Colorado and Maine.
Spessartine forms a solid solution series with the garnet species almandine.[3][4] 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 [5] .
References
- ^ a b c d Gemological Institute of America, GIA Gem Reference Guide 1995, 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
- ^ "Spessartine from Latinka, Bulgaria:". http://www.mindat.org/locentry-216291.html.
Spessartine crystal on muscovite matrix from Tanzania
Manganese minerals Borates Carbonates Oxides SimpleMixedBirnessite · Bixbyite · Ferrocolumbite · Ferrotantalite · Galaxite · Jacobsite · Manganotantalite · Psilomelane · Romanèchite · Tantalite · Todorokite · UmberPhosphates Childrenite · Graftonite · Lithiophilite · Natrophilite · Purpurite · Triplite · Triploidite · ZanazziiteSilicates Babingtonite · Bixbite · Braunite · Brownleeite · Calderite · Chloritoid · Eudialyte · Glaucochroite · Jeffersonite · Knebelite · Ottrelite · Piemontite · Pyroxferroite · Rhodonite · Spessartine · Sugilite · Tephroite · Zakharovite · ZircophylliteSulfides Other Axinite (borosilicate) · Geigerite (arsenate) · Manganese nodule (various) · Samsonite (Sulfosalt) · Zincobotryogen (sulfate)
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