4 Pack White Natural Terrazzo Coasters with Large Marble Flecks and Protective Cork Backing. Terrazzo is a composite material made from chips of Marble, Quartz and Granite that is held together with resin. Terrazzo coasters are a durable and stylish option for protecting your furniture. The unique material gives them a varied and eye-catching appearance, while their heat and moisture-resistant properties make them a practical choice for everyday use. Each Coaster measures 4" x 4 Square.