Hibonite
| Hibonite | ||
|---|---|---|
Specific gravity 3.84 | | |
| Optical properties | Uniaxial (-) | |
| Refractive index | nω = 1.807(2), nε = 1.79(1) | |
| Pleochroism | O = brownish gray; E = gray | |
| References | [2][3] | |
Hibonite is a mineral with the chemical formula (Ca,Ce)(Al,Ti,Mg)12O19, occurring in various colours, with a hardness of 7.5–8.0 and a hexagonal crystal structure. It is rare, but is found in high-grade
Ca-Al-rich inclusions found in some chondritic meteorites. Hibonite is closely related to hibonite-Fe (IMA 2009-027, (Fe,Mg)Al12O19)) an alteration mineral from the Allende meteorite.[4] Hibonites were among the first minerals to form as the disk of gas and dust swirling around the young sun cooled.[5]
A very rare gem, hibonite was discovered in 1953 in Madagascar by Paul Hibon, a French prospector.[6]
Colour
Hibonite can vary in colour, from a bright blue, to green, to orange, to a nearly black deep brown. The colour is related to the degree of oxidation; meteoritic hibonite tends to be blue.[7]
See also
References
- S2CID 235729616.
- ^ "Handbook of Mineralogy" (PDF).
- ^ "Hibonite: Hibonite mineral information and data". www.mindat.org.
- ^ "IMA Mineral List with Database of Mineral Properties". rruff.info.
- ^ "A Year in Review and a Look to the Future". Field Museum of Natural History. January 11, 2019. Retrieved 4 December 2021.
- ^ "Hibonite gemstone information". www.gemdat.org.
- .
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