The Luke occurrence consists of a quartz vein about 1 metre wide with stringers of quartz on the margins in a diorite sill of the Proterozoic Moyie Intrusions within sediments of the Helikian Purcell Supergroup. The vein strikes 150 degrees and dips 80 degrees west. Sulphides consist of pyrite and minor chalcopyrite. Hand sorted sulphides ran as high as 9.4 per cent copper with traces of gold (Minister of Mines Annual Report 1919). The vein was trenched in 1919-1920.