The Ray 12 showing is on the west bank of the Similkameen River, 10.5 kilometres south-southwest of Princeton.

This area along the Similkameen River, in the vicinity of Smelter Lakes, is underlain by intrusive rocks of the Lost Horse Intrusions and the Smelter Lake stock (Copper Mountain Intrusions), both of Early Jurassic age, and volcanics of the Upper Triassic Nicola Group. The Nicola Group volcanics were previously included with the Wolf Creek Formation (Geological Survey of Canada Memoir 171). All units are unconformably overlain to the east by volcanics and sediments of the Eocene Princeton Group.

Two small streaks of chalcopyrite and pyrite occur in diorite of the Smelter Lake stock, near a northeast-striking microsyenite dyke of the Lost Horse Intrusions. Two short adits follow the sulphide streaks.

Similar mineralization occurs on the west bank of the river 370 metres to the south. Here, two streaks of chalcopyrite and magnetite, 15 and 25 centimetres wide, are hosted in diorite. This mineralization is developed along fractures striking north-northeast for up to 1.5 metres.