Londonite
Londonite is named after Dr. David London, Professor of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma, USA, for his contributions to the understanding of granite pegmatites.
Londonite forms colourless, white, sulfur-yellow, pale yellow, pale yellow-green crystals with vitreous lustre.
Londonite is a very rare gem - it is found only in a very limited series of pegmatites in Madagascar. Gemmy faceted material is rare.
Londonite forms colourless, white, sulfur-yellow, pale yellow, pale yellow-green crystals with vitreous lustre.
Londonite is a very rare gem - it is found only in a very limited series of pegmatites in Madagascar. Gemmy faceted material is rare.
| General Information | ||||||||||||||||||
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| Chemical Formula |
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| Physical Properties of Londonite | ||||||||||||||||||
| Mohs Hardness | 8, Handbook of mineralogy (2001) | |||||||||||||||||
| Specific Gravity | 3.34, Handbook of mineralogy (2001) | |||||||||||||||||
| Tenacity | Brittle, Handbook of mineralogy (2001) | |||||||||||||||||
| Fracture | Conchoidal, Handbook of mineralogy (2001) | |||||||||||||||||
| Optical Properties of Londonite | ||||||||||||||||||
| Optical Character | Isotropic, Handbook of mineralogy (2001) | |||||||||||||||||
| Colour | ||||||||||||||||||
| Colour (General) | Colorless, white, sulfur-yellow, pale yellow, pale yellow-green., Handbook of mineralogy (2001) | |||||||||||||||||
| Transparency | Transparent,Translucent, Handbook of mineralogy (2001) | |||||||||||||||||
| Lustre | Vitreous, Handbook of mineralogy (2001) | |||||||||||||||||
| Crystallography of Londonite | ||||||||||||||||||
| Crystal System | Isometric, Handbook of mineralogy (2001) | |||||||||||||||||
| Habit | As portions of Cs-rich material heterogenously distributed throughout crystals, patchy, exsolutionlike, and in veinlets; to 7 cm, Handbook of mineralogy (2001) | |||||||||||||||||
| Geological Environment | ||||||||||||||||||
| Where found: | An uncommon component of granite pegmatites, in the central zones and in miarolitic cavities., Handbook of mineralogy (2001) | |||||||||||||||||
| Further Information | ||||||||||||||||||
| Mineral information: | Londonite information at mindat.org | |||||||||||||||||
| Significant Gem Localities | ||||||||||||||||||
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