The Winlaw occurrence is located on the south side of the north fork of Winlaw Creek, approximately 6 kilometres east of Winlaw.

The area is underlain by Middle to Late Jurassic Nelson Intrusions.

The Winlaw quartz body is a massive irregular pod of pegmatitic quartz exposed over an area approximately 35 by 26 metres. A perthite/quartz intergrowth, with euhedral perthite crystals reaching 15 centimetres in length, borders the quartz body on the south, west and northwest sides. Rocks surrounding the pegmatitic facies are mainly porphyritic syenites. The northeast extent of the quartz is limited by granitic rocks while the eastern margin is covered by overburden. Jointing is strongly developed in three directions within the quartz and some of the joints host fine-grained specularite and hematite staining. Large vugs, containing remnant fluorite and second generation quartz crystals, typically reach 15 by 15 by 4 centimetres in size.

In 1976, it was estimated that 100,000 tonnes of high-grade silica rock, with assays up to 99.6 per cent silica, were present (Exploration in British Columbia 1976, page 207). A small quarry (Snowdrift), 10 by 20 metres, produced 500 tonnes of silica in 1971.