The Copper Coin showing occurs near the northwest corner of Porcher Island about 2.0 kilometres southwest of the Surf Point Mine (103J 017).

A 2 to 3.7 metre wide quartzose shear zone strikes about 105 degrees and dips 45 degrees north within Paleozoic-Mesozoic chlorite schist. Cretaceous to Tertiary intrusions of the Coast Plutonic Complex occur just over 1.0 kilometre to the west. Within the shear zone, a quartz vein about 75 metres long is mineralized with aurif- erous pyrite and minor chalcopyrite. A 0.8 metre sample assayed 1.7 grams per tonne gold, 6.9 grams per tonne silver and trace copper (Minister of Mines Annual Report 1930, page 72).

About 500 metres north of the quartz vein, along the shore, a siliceous and feldspathic replacement zone is mineralized with pyrite and chalcopyrite.