The Newcastle Island sandstone quarry was the first quarry developed in the region (CANMET Report 452). It provided building stone used to construct the San Francisco Mint (1873), the British Columbia Penitentiary (1875), Esquimalt Graving Dock (1880), Lord Nelson School in Vancouver (1911), and Bank of Montreal (1907) and Christ Church Cathedral in Victoria (1955). This important quarry is located on the west shore of Newcastle Island, opposite Pimbury Point, and lies within the Newcastle Island Provincial Park. No production figures are available.

The area is underlain by the Upper Cretaceous Nanaimo Group, Protection Formation (the McMillan and/or Cassidy members). The sandstone is medium-grained (0.6 to 2.0 millimetres), displays a uni- form texture and an attractive light grey tone with a speckled (salt and pepper) appearance.

Thin sections show 50 to 60 per cent of the rock is comprised of closely packed, fresh, angular to subangular quartz grains, commonly 0.5 millimetres in size, with interstitial orthoclase, plagioclase and biotite. The orthoclase is altered to sericite.

The worked face is 73 metres in length with a vertical height of 2 to 6 metres. Bedding strikes northwest and dips gently southwest. A prominent set of joints have a north-northeast strike and dip steeply east. Over 85 per cent of the joints and fractures measured are spaced more than 100 centimetres apart with 57 per cent greater than 300 centimetres apart.

Reserves of light grey sandstone lie northeast of the quarry. Measurements of joint fracture density suggest blocks greater than 3 by 3 by 3 metres may be available.