The Ptarmigan quartzite silica occurrence is located between Ptarmigan and Dome creeks, approximately 6 kilometres southeast of the community of Dome Creek.

The area is underlain by quartzites of the Lower Silurian Nonda Formation or equivalent of the Lower Cambrian and/or Hadrynian Yanks Peak Formation. The quartzites generally strike 60 degrees with dips of 45 to 65 degrees and are underlain by a phyllite unit with and 3 to 5 metre transition zone.

Locally, quartzite layers are quite pure and typically weather white. The sedimentary quartz grains are generally well rounded and well sorted and the rock is well indurated due to the development of secondary silica cement. Quartz grains typically average from 0.5 to 1.0 millimetre in diameter.

In 2010, a program of geological mapping and sampling of quartzite beds was completed. Fourteen of fifteen samples from the quartzite beds returned between 97.4 to 98.54 per cent silica (Assessment Report 32528).

In 2024, a small number of samples were collected by C. Healey for data verification for the writing of a technical report on the property (Healey, 2024). In late 2024, Silicon Metals conducted a rock sampling program, collecting 225 samples. The samples had an average purity of 98.49 per cent SiO2 (Press Release, Silicon Metals Corp. June 4, 2025).