A rare blue or violet mineral occurring typically as needles and fibrous masses in gneiss and schist. It consists of an aluminium and iron borosilicate.
- ‘Little known from the east coast, important deposits of dumortierite exist in Rochester and Oreana, Nevada.’
- ‘Beautiful blue semi-precious dumortierite nuggets are accented by sparkling 8mm clear Swarovski crystals.’
- ‘Detrital dumortierite infrequently has been found in the heavy mineral fraction of sediments.’
- ‘Blue quartz, also called dumortierite, is a stone of order that can enhance organizational abilities, self-discipline, and orderliness.’
- ‘Although dumortierite has a reputation for being difficult to polish, we have found it works easily and polishes well with diamond.’
Late 19th century from the name of V.-E. Dumortier (1802–76), French geologist, + -ite.
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