Suilven from Stac Pollaidh ridge

Suilven and the mountains of Assynt beyond, viewed from the Stac Pollaidh ridge. Loch Sionasgaig is in the foreground.

Suilven is comprised of Torridonian Sandstone which rests unconformably on the high-grade metamorphic basement rocks of the Lewisian Gneiss which forms the 'knock and lochan' landscape in the middle ground. There is a time gap of about 700 million years separating the two rock units.