Thirstystone Spiral Coaster Set of 4x Sun Natural Sandstone Eco-Friendly Coaster Size: Approx 4.25” x 4.25” * Sandstone coasters are made from natural sandstone, which is a sedimentary rock composed of sand-sized minerals or rock grains. Sandstone is a sustainable and environmentally friendly material. * These Sandstone Coasters will continually absorb condensation from beverages. Sandstone is also heat tolerant, making it a great choice for protecting tables and countertops from hot beverages. * Sandstone is a durable material that can withstand wear and tear from daily use. Sandstone has a natural grip and non-slip surface that keeps glasses and mugs from sliding around when in use. * cork bottom coasters * rare collectible coaster set New in box. The box shows minor wear Thirstystone Coasters, Spiral Coaster Set, 4x Sun Natural Sandstone Coaster, Eco-Friendly Coaster, stone Coaster