Natural Stone Resources SLTCALGLD2424G-5RFCC 24" x 24" 5cm California Gold Gauged Rock Face Slate Column Cap. Natural Stone Resources is a premier importer & distributor of quality natural stones from around the world. Whether you're looking to add coping to your masonry walls, columns, landscape, steps, or pools, the California Gold Gauged Column Cap is a beautiful choice. Includes a gauged finish.