DINOSAURS ROCK Purple Amethyst Color - Dyed Sliced Agate Coasters - Set of 4 - Exclusive! Set of 4 Sliced Geode Agate Coasters - DINOSAURS ROCK exclusive! Vivid Purple (Amethyst-dyed color) - Actual product may vary. Photo is representative. Unique decorative item for entertaining With rubber "feet" to protect furniture surface and prevent slippage Great gift! Large 3.5"-4"