The Lewisian gneiss stone circle at Callanish on an early autumnal morning with clouds forming above, Isle of Lewis, Outer Hebrides, Scotland, United Kingdom, Europe

The Lewisian gneiss stone circle at Callanish on an early autumnal morning with clouds forming above, Isle of Lewis, Outer Hebrides, Scotland, United Kingdom, Europe

Giant Lewisian gneiss rock on a showery evening at Mealista on the south west coast of Lewis, Isle of Lewis, Outer Hebrides, Scotland, United Kingdom, Europe

Lewisian gneiss, one of the oldest rocks on earth formed 2 billion years ago, Isle of Lewis, Outer Hebrides, Scotland, United Kingdom, Europe

yellow mountain saxifrage, saxifraga aizoides, on lewisian gneiss, scotland