Red Beach The volcanic geology of Santorini leads to an unusually wide variety of colored pebbles and sands. The volcanic rock is naturally black, and most of the beaches around the island are accordingly from black sand. The earlier part of each eruption ejects lighter-colored tuff, which can be found forming the white beaches. And when water is involved in an eruption, the high concentrations of iron oxidize to rust turning the rock a ruddy hue. This transformed one part of the island into a Martian landscape of calving boulders, albeit one with a very nice beach. Copyright 2006, J. S. Pezaris AREADNE | Email | Archive |