Cot boulders, 2017. Three-drop earring.Three drop Cornish Tin earrings with sterling silver hooks, based on the iconic 'dinosaur egg' rocks found at Cot Valley. Where Cot Valley meets the coast, the stream trickles over and through a raised beach of spherical white pebbles the so called dinosaur eggs. Visitors often try to stack these round boulders by balancing them in piles. Kurt Jackson. Three drop earring Cornish tin 0. 75cm, 1cm and 1. 5 cm diameters (approx)