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| Formula | MgO |
| | Optic class & sign | Isotropic |
| | Relief | High |
| | Refractive Index | 1.736 -1.756
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|
| n increases with Fe |
| | Birefringence | Zero |
| | Colour | Colourless (Fe-poor) to pale yellow or pale brown (Fe-rich) |
| | Zoning | |
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| Form | Habit | Granular |
| | | Surface | Originally euhedral cubes or octahedral, anhedral remains if altered |
| | Cleavage | 3 sets {001} perfect |
| | Twinning | {111}, but commonly not identified in thin section |
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| Reaction textures | Retrograde hydration to form brucite |
| | Alteration / decomposition | Brucite |
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| Occurence | Ign | |
| | | Met | High-temperature magnesian carbonate rocks |
| | | Sed | |
| | | Hyd | |
| | | Other | |
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| Distinctive properties | High relief, isotropic, cleavage, alteration, restricted occurrence |
| | Additional comments | |
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