The Natural Shell Stone is mined in the mountains of Turkey. We import this Natural Shell Stone then Manufacture the Coasters here in the USA. Each Coaster is made of genuine Shell Stone that is absorbent in nature. Shell Stone is known as a type of limestone, but density of the stone is similar to Marble. Shell Stone is strong and stays cool to the touch. Coasters have a cork backing which protects your surfaces from scratches and stains. Artistic designs are printed on the surface of each coaster. These attractive Coasters add elegance and distinction to your space. Because this is natural stone marble, the coasters may vary is shape and color. The Coasters are made for long lasting use. Comes wrapped in twine with hang tag attached. Each Coaster measures 4” x 4” x 0.43”.