The Topaz showing is located very close to Highway 3 and just west of the confluence of Topaz Creek with Summit Creek, about 19 kilometres west-northwest of Creston.

The Topaz and Toby groups, comprising 15 claims, were owned in 1969 by Magog Mining Co. Ltd. Work included magnetic and electromagnetic surveys over Topaz 1-5 and trenching.

The showing is hosted by relatively high grade metamorphic rocks (near the boundary between staurolite-kyanite facies to the west and kyanite-sillimanite facies to the east), developed from sedimentary rocks of the Aldridge Formation (Middle Proterozoic Purcell Supergroup). The original showing consisted of galena, sphalerite and cassiterite in a quartz vein; chalcopyrite and pyrrhotite are disseminated in a diorite sill. Traces of nickel and silver are reported.

This showing was covered by a magnetic and electromagnetic survey in 1968 for Magog Mining Ltd.; several magnetic anomalies were found worthy of follow-up, likely due to concentrations of pyrrhotite. The area was subjected to a geochemical survey in 1984 for Greenwich Resources, which did not locate the original showing, and disclosed only weak anomalies for copper and zinc.

Greenwich Resources Inc. held the property in 1984; a geochemical silt survey was reported.