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Chemical Formula | Mn3Al2Si3O12 |
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Composition | Manganese aluminum silicate. The manganese is often replaced by some magnesium and iron |
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Variable Formula | (Mn,Mg,Fe)3Al2Si3O12 |
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Color | Brown, orange, pink, brownish-red |
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Streak | Colorless |
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Hardness | 7 |
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Crystal Forms and Aggregates |
(Isometric) Occurs in single dodecahedral and trapezohedral crystals, sometimes well-developed. Also occurs in crystal clusters and in grainy aggregates. |
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Transparency | Transparent to translucent |
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Specific Gravity | 4.2 |
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Luster | Vitreous |
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Cleavage | None |
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Fracture | Conchoidal to uneven |
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Tenacity | Brittle |
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Other Names |  Spessartite |
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In Group | Silicates ; Nesosilicates ; Garnet group |
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All About | Spessartine is a Garnet, belonging to the Garnet
group.
The Garnet group is a small group of closely related
minerals. The members of the Garnet group are isomorphous, and some of them freely
intermingle. They vary only slightly in physical
properties, and some of them may be so similar that they
are indistinguishable from one another without x-ray
analysis. The most common members are: Pyrope, Almandine, Spessartine, Grossular, Andradite, and Uvarovite. The minerals in the Garnet group are called "Garnets". All Garnets are hard and many are fit for gem use. Unless articulate, most mineral and gem dealers don't refer to garnets by their true name (i.e. Spessartine), but by the name "Garnet". The garnets as a group occur in all colors (except for blue). For more information about garnets, see the Garnet group. |
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Uses | Spessartine of gem quality is faceted into
gems. Specimens are also popular among mineral
collectors. See the gemstone section on garnet |
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Striking Features | Color, crystal forms, and hardness |
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Popularity (1-4) | 2 |
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Prevalence (1-3) | 2 |
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Demand (1-3) | 1 |
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Distinguishing Similar Minerals |
Pyrope - Color is deeper red Grossular - Very hard to distinguish without complex methods Andradite - Very hard to distinguish without complex methods |
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Commonly Occurs With |
Quartz, Albite, Muscovite, Tourmaline, Riebeckite, Rhodonite |
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Noteworthy Localities |
Spessartine is not as common as most other
Garnets and its occurrences are much more limited. It
occurs in Iskardu, Pakistan; Sri Lanka; Sanyeshan,
Guangdon Province, China; Broken Hill, New South Wales,
Australia; and Berilanda, Ceara, Brazil. In the U.S., it is found in Ramona, San Diego Co., California; Ely, White Pine Co., Nevada; the Thomas Range, Juab Co., Utah; Ruby Mountain, near Nathrop, Chaffee Co., Colorado; and Amelia Court House, Amelia Co., Virginia. |
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Picture Icon Links |
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Picture Links | Sorry. No Images currently available. |
