The Peridotite Creek chromite prospect is on the southeast side of a very steep razor back ridge (elevation 2790 metres) northwest of the headwaters of Peridotite Creek, and is within ultramafic rocks of the Shulaps Ultramafic Complex. Host rocks are mostly dunite to dunitic peridotite, with orthopyroxenite, olivine orthopyroxenite and harzburgite. All rocks have been slightly serpentinized and are limonitic (orange-rust coloured) on surface. Knobby warty-surfaced outcrop is due to the differential weathering of olivine and enstatite, the latter being more resistant. The age of the Shulaps complex is uncertain but is now thought to be Permian and older. An amphibolite knocker within the complex gave an age date of Early Permian; this has been interpreted as the age of cooling following metamorphism, hence the Permian and older age date for the entire Shulaps Ultramafic Complex (Fieldwork 1990, pages 80-81).

Chromite occurs as disseminated grains and grain clots within (predominantly) dunitic layers in layered harzburgite-dunite. Chromite grains commonly form trains that are stratabound within dunitic rocks and are continuous for a metre or so along layering. The area that contains disseminated chromite is at least 10 metres by 6 metres wide. The exposure is on a very steep ridge side and it is hard to assess the abundance and distribution of the chromite.