The Shingle Creek porphyry is located 3.75 kilometres west of Penticton, British Columbia on the Penticton Indian Reserve, adjacent to Shingle Creek.
The porphyry consists of an irregularly-shaped lenticular stock (2 by 7 kilometres) concaved to the south with several large offshoot dikes at the western boundary. It is characterized by large twinned potassium feldspar crystals (1 to 10 centimetres), smaller plagioclase phenocrysts (up to 1.5 centimetres), quartz bipyramid (Herkimer diamond) euhedra/subhedra (up to 1 centimetre) and minor mafic minerals (magnetite and biotite) in a medium to fine grained matrix of similar composition. The stock intrudes diorite and granodiorite phases of the Okanagan batholith and part of its own volcanic pile that consists of rhyolite tuff and breccia containing large broken sanidine phenocrysts.
The bipyramidal quartz crystals (Herkimer diamonds) and the large, commonly twinned, sanidine phenocrysts that weather free of the hostrock are of interest to mineral collectors.
The age the porphyry, based on K-Ar analysis of fine grained, biotite inclusions within sanidine phenocrysts is 52.4 +/- 1.9 Ma (Map 35-Preliminary).