A small amount of mica was mined from the north shore of Baker Inlet, east of Grenville Channel, 60 kilometres south-southeast of Prince Rupert.
A belt of metasediments of the Alexander Terrane, up to 1 kilometre wide, extends southeast from Telegraph Passage along the east side of Grenville Channel for 60 kilometres. The belt is locally intruded and bounded to the northeast by quartz monzonites of the Coast Plutonic Complex.
A pegmatitic zone outcrops along a bluff at 88 metres elevation, 300 metres north of Baker Inlet, within northwest trending mica schists. The zone strikes north, dips 17 degrees west and has been traced along strike for 60 metres. Trenching has uncovered pockets and lenses of good grade mica within the pegmatite up to 3 metres long and 1.5 metres wide. Pulverizing tests carried out by ore testing labs in Ottawa are as follows (Minister of Mines Annual Report 1934, page B10):
------------------------------------------
Size Per cent of Mica grade
fraction raw feed (per cent)
+100 mesh 77 99
-100 to +200 88 99
-200 mesh 68 80
A second deposit of mica outcrops in the vicinity, at 120 metres elevation, 180 metres from Baker Inlet. A micaceous zone in altered mica schists has been traced for 200 metres and contains 10 to 90 per cent sericite across widths of 0.6 to 2.1 metres (Minister of Mines Annual Report 1940, page 99). In 1940, 73 tonnes of crude sericite mica were shipped from this deposit by P.M. Ray to Fairey & Company in Vancouver. About 71 tonnes was also shipped in 1941.
