The Cayoosh Creek quarry is 500 metres west of Cayoosh Creek, 27 kilometres southwest of Lillooet.
The area southwest of Lillooet is underlain by Jurassic to Tertiary Coast Plutonic Complex rocks which intrude the Mississippian to Jurassic Bridge River Complex (Group).
The quarry is located in a fine to medium-grained quartz monzonite plug which intrudes Bridge River Group sedimentary rocks. The quarry area is characterized by horizontal ledges several metres-thick of massive monzonite overlain by a more densely fractured zone. The existing quarry face allows removal of blocks several cubic metres in size. The stone is homogeneous with uniform texture. No dark inclusions can be seen on quarry faces. The quarried blocks are split into masonry and facing shapes and marketed under the trade name Arctic White granite. It has been widely used around Whistler and in the Vancouver area.
The quarry is operated on a seasonal basis by Northwest Granite Company, an affiliate of Marchesi Marblecraft Ltd. of Burnaby. Some 300 to 400 tonnes of granite were produced for building facings in 1990, the first year of operation (L. Marchesi, personal communication, 1991).
Arctic White stone is a bright white, fine to medium-grained quartz monzonite. The texture is very uniform but has a strong planar fabric defined by biotite. Major minerals are white plagioclase, orthoclase, microcline, clear colourless quartz and black biotite. Minor constituents are sphene, (clino?) zoisite and chlorite after biotite.
The rock is quite fresh with only minor alteration of biotite to chlorite and sericitization of plagioclase. The polished surface is good (7-8/10) and pitting is limited to crystal corners where cleavage planes intersect the surface. There is no staining as iron oxides or sulphides are essentially absent.