The Bonacci showing outcrops along the northwest bank of Christian Creek, below the Kettle Valley Railway, 12 kilometres north-northeast of Princeton.
A pyritic zone, 350 metres long and up to 180 metres wide is developed in quartz monzodiorite, monzonite and diorite in the outer part of a zoned intrusion, 1.2 kilometres wide. This stock intrudes andesitic to basaltic volcanics of the Upper Triassic Nicola Group.
The monzodiorite exhibits clay, epidote and chlorite alteration. Mineralization consists of pink quartz-carbonate veinlets carrying chalcopyrite and minor pyrite and galena.
The west end of the pyritic zone was tested by two adits excavated in 1942. Kennco Explorations (Western) Ltd. and Amax Exploration completed geological, geophysical and soil geochemical surveys over the showing in 1959 and 1969. Additional geological mapping and petrographic studies were conducted by Quintana Minerals Corporation in 1977 and by P. Peto in 1989.