Craignure Mine

Site of Special Scientific Interest · 56.1601, -5.2297

Condition (NatureScot)

Unfavourable Declining (1)
UnitFeatureConditionArea (ha)Assessed
F1 Mineralogy of Scotland Unfavourable Declining 2017-04-19

Geology & landscape

Rock Type: Quartzite

Landscape processes: Volcanic / Igneous

Description

CRAIGNURE MINE Exploration for base metals in the pillow lavas and sills of the Dalradian Tayvallich volcanics in the Loch Fyne area led to the development of copper/nickel mines at Craignure and Coille-Bhraghad. The latter is largely destroyed and the dumps used as hardcore, but the smaller Craignure Mine workings are still visible adjacent to a forestry road. Two adits are visible, one being still open. It appears the ore forms a replacement body in quartzite at the base of a very altered epidiorite sill, the whole dipping at 40° to the north. Dumps in the forest south of the road are small but extensive and small areas of high grade ore can be located. These consist of rapidly oxidising pyrrhotite and pentlandite with minor chalcopyrite. Brown iron oxides stained with green nickel secondary minerals surround the sulphides. This is probably the only locality in Britain where large pieces of pentlandite can be found and it contrasts with the niccolite mineralisation seen in a not dissimilar geological environment at Talnotry (q.v.) in South Scotland. Identification of copper and nickel secondary phases could also be of interest.