Ben Wyvis is primarily composed of Moine schist, which was formed as sediment around 1,000 to 870 million years ago during a period when the landmass that is now Scotland was covered by shallow seas. As the amount of sediment increased the layers underwent metamorphism due to the increased temperature and pressure, resulting in the formation of a hard, water-resistant rock. This schist was subjected to further upheaval during the Caledonian orogeny, leading to formation of waves and folds which are visible in the rocks.