Building stone from this sandstone quarry, located on the west coast of Gabriola Island just south of Descanso Bay, was used to construct the main Post Office in Victoria, the Federal Life Building (Williams Building) and the Holy Rosary Cathedral in Vancouver. Blocks 1.4 metres across by 1.5 metres deep, were quarried for use as grindstones in pulp mills in the coast area. No production figures are available.

The area is underlain by the Upper Cretaceous Nanaimo Group, Gabriola Formation. The sandstone is medium-grained (0.6 to 2.0 millimetres), displays an even texture and has a light to medium brown tone. Small angular quartz crystals and blades of biotite (up to 3.0 millimetres) speckle the rock. Occasional pebbles (up to 4.0 centimetres) and coarse sand concretions disrupt the continuity of the bedding.

In thin section, the quartz grains range from 0.25 to 1.5 millimetres and comprise 70 per cent of the rock. Other minerals include orthoclase, plagioclase and biotite. Alteration of feldspar to sericite is pronounced.

The quarry has a length of 45 metres, with worked faces between 2 to 15 metres high, developed parallel to northeast striking joints. Vertical and horizontal joints are widely spaced with 90 per cent spaced more than 100 centimetres apart. Beds dip 10 to 15 degrees northeast and strike northwest.

Potential reserves of stone extend 20 metres southeast of the worked face and beyond this the area is covered by overburden.