A quarry on Saltspring Island was developed in sandstone of the Upper Cretaceous Nanaimo Group, Cedar District Formation. The stone is medium-grained (0.06 to 2 millimetres), has a uniform texture and a moderate light to dark brown colour. Exposed surfaces of stone are prone to disintegration. The worked face extends intermittently for 150 metres along a vertical bedding plane and is cut by steeply dipping north-northeast striking joints. Vertical joints are widely spaced (up to 16 metres) while flat-lying bedding planes are regularly spaced between 2 to 4 metres.

Saltspring sandstone was used to construct a portion of the main Victoria Post Office but no production figures are available. Potential reserves of sandstone extend 20 metres north and east of the worked face. A developed residential lot immediately east of the quarry will restrict expansion.