Iron-magnesium-aluminium borosilicate grandidierite has been found in a K-rich metasediment at Vestpolltind, Hinnøya, northern Norway. This is only the third certain locality for this mineral. It occurs together with orthoclase, quartz, garnet, biotite, rutile and ilmenite. The K-rich metasediments are associated with granulite-facies Mn-bearing iron formations, and seem to be of submarine origin. P-T estimates for the metamorphism in the area give ˜10kb and 850--900°C.
The first occurrence of grandidierite in Norway. Contribution to the mineralogy of Norway, no. 59.