An uncommon primary mineral in the intermediate zone of a granite pegmatite enriched in manganese and fluorine.
IMA Status:
Approved IMA 1986
Locality:
From the Gotcha claim, on an island in Cross Lake, Manitoba, Canada. Link to MinDat.org Location Data.
Name Origin:
To honor Emeritus Professor Robert Bury Ferguson (1920- ), Canadian mineralogist, University of Manitoba, Winnipeg, Canada, especially for his contributions to pegmatite mineralogy.
Chemical Formula: 