Agate is a rock consisting primarily of cryptocrystalline silica. Agate is characterized by its fineness of grain and variety of color. Agates are classically associated with volcanic rocks and can be common in certain metamorphic rocks. Agate is thought to increase inner stability, composure, maturity, and help with protection. These unique coasters will be the focus of your table. They come in five different colors blue, pink, purple, brown, and black. There are four coasters in each set and they are approximately 5" x 4.5". buy AGATE SLICE HANDMADE COASTER SET from https://crystaljoys.com/products/coaster-set at $ 45.00.