Malaia garnet
Malaia garnet or Malaya garnet is a gemological varietal name for light to dark slightly pinkish orange, reddish orange, or yellowish orange garnet, that are of a mixture within the pyralspite series pyrope, almandine, and spessartine with a little calcium. The name Malaia is translated from Swahili to mean, prostitute. It is found in east Africa, in the Umba Valley bordering Tanzania and Kenya.[2]
| Malaia garnet | |
|---|---|
| General | |
| Category | Varietal name |
| Formula (repeating unit) | (Mg,Mn)3Al2(SiO4)3 [1] |
| Crystal system | cubic [1] |
| Identification | |
| Color | light to dark slightly pinkish orange, reddish orange, yellowish orange |
| Cleavage | none, may show indistinct parting [1] |
| Fracture | conchoidal [1] |
| Mohs scale hardness | 7 - 7.5 [1] |
| Luster | vitreous [1] |
| Specific gravity | 3.78 - 3.85 [1] |
| Polish luster | vitreous to subadamantine[1] |
| Optical properties | Single refractive, often anomalous double refractive [1] |
| Refractive index | 1.760 (+.020, -.018) [1] |
| Birefringence | none [1] |
| Pleochroism | none [1] |
| Ultraviolet fluorescence | inert [1] |
| Absorption spectra | strong lines at 410, 420, 430nm, that may merge to form cutoff below 435nm. Also some combination of lines at 460, 480, 504, 520, or 573nm.[1] |
References
- (Gia), Gemological. Gem Reference Guide. City: Gemological Institute of America (GIA), 1988. ISBN 0-87311-019-6
- Garnet(Almandine, Rhodolite, Pyrope, Demantoid, Tsavorite, Hessonite, Grossular, Spessartine) Course notes at the Department of Geological Sciences, The University of Texas at Austin website, accessed January 27, 2007
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