Marble X is for those seeking greater durability and avoidance of rusting and corrosion. Marble X is their trade name for a non-metallic compound that includes ground marble particles. The finish on their MarbleX products is premium grade and resists peeling, chipping, and harmful UV rays. Being an injection molded material, MarbleX is strong and lends itself to the production of fine design details. marble is the most durable material for making outdoor lighting fixtures.