Ekanite
| Ekanite | |
|---|---|
| General | |
| Category | Silicate mineral |
| Formula (repeating unit) | Ca2ThSi8O20 or (Ca,Fe,Pb)2(Th,U)Si8O20 |
| Crystal system | Tetragonal |
| Identification | |
| Color | Green, yellow, dark red |
| Crystal habit | Pyramidal crystals, granular to massive |
| Cleavage | Distinct on {101} |
| Fracture | Brittle, uneven |
| Mohs scale hardness | 4.5 |
| Luster | Vitreous |
| Streak | White |
| Diaphaneity | Transparent to translucent |
| Specific gravity | 2.95 - 3.28 |
| Optical properties | Uniaxial (-) 2V = 10 - 15° |
| Refractive index | nω = 1.580 nε = 1.568 |
| Birefringence | δ = 0.012 |
| Other characteristics | Radioactive, metamict |
| References | [1][2][3] |
Ekanite is an uncommon mineral notable primarily as being among the very few gemstones that are naturally radioactive. Most ekanite is mined in Sri Lanka, although deposits also occur in Russia and North America. Clear and well-colored stones command the best prices, but such stones are rare; the mineral's radioactivity tends to degrade the crystal matrix over time in a process known as metamictization.
Ekanite was first described in 1955 by F. L. D. Ekanayake,[4][5] and it is named after him.[6]
References
- ↑ http://www.mindat.org/min-1361.html Mindat
- ↑ http://rruff.geo.arizona.edu/doclib/hom/ekanite.pdf Handbook of Mineralogy
- ↑ Ekanite Mineral Data at Webmineral
- ↑ New Minerals, American Mineralogist
- ↑ B. W. Andeson, G. F. Claringbull, R. J. Davis, and D. K. Hill (1961). "Ekanite, a new metamict mineral from Ceylon". Nature 190 (4780): 997. Bibcode:1961Natur.190..997A. doi:10.1038/190997a0.
- ↑ New Minerals, American Mineralogist
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