Hibonite
Hibonite is named after Paul Hibon, a French prospector who discovered the mineral in Madagascar.
Hibonite is a very rare gem. Stones which are large enough or transparent enough for faceting are very sparse.
Hibonite is slightly radioactive.
Hibonite is a very rare gem. Stones which are large enough or transparent enough for faceting are very sparse.
Hibonite is slightly radioactive.
| Physical Properties of Hibonite | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Mohs Hardness | 7.5 to 8, Handbook of mineralogy (2001) | ||||||||
| Specific Gravity | 3.84, Handbook of mineralogy (2001) | ||||||||
| Cleavage Quality | Good, Handbook of mineralogy (2001) | ||||||||
| Fracture | Sub-Conchoidal, Handbook of mineralogy (2001) | ||||||||
| Optical Properties of Hibonite | |||||||||
| Refractive Index | 1.79 to 1.807, Handbook of mineralogy (2001) | ||||||||
| Optical Character | Uniaxial/-, Handbook of mineralogy (2001) | ||||||||
| Pleochroism | Brownish gray - gray, Handbook of mineralogy (2001) | ||||||||
| Colour | |||||||||
| Colour (General) | Brownish black to black; reddish brown in thin fragments., Handbook of mineralogy (2001) | ||||||||
| Transparency | Translucent, Handbook of mineralogy (2001) | ||||||||
| Lustre | Vitreous, Handbook of mineralogy (2001) | ||||||||
| Crystallography of Hibonite | |||||||||
| Crystal System | Hexagonal, Handbook of mineralogy (2001) | ||||||||
| Habit | Prisms, platy or steep pyramidal, to 4 cm., Handbook of mineralogy (2001) | ||||||||
| Geological Environment | |||||||||
| Where found: | In metamorphosed limestone, pyroxenite, gneiss, and granulite of the amphibolite to granulite facies; also alluvial. A common accessory in Ca–Al-rich inclusions in some carbonaceous chondrites., Handbook of mineralogy (2001) | ||||||||
| Further Information | |||||||||
| Mineral information: | Hibonite information at mindat.org | ||||||||
| Significant Gem Localities | |||||||||
| |||||||||