Coasters are an often overlooked home furnishing that is particularly necessary if you\'re prone to drinking out of mugs for your daily caffeine fix. For a stylish yet still practical coaster set, consider Petra. Petra is a set of four coasters made from natural lava stone, an igneous volcanic rock made up of solidified molten lava. This unique material makes for a beautiful and individual coaster set that is incredibly sturdy and eye catching. Petra comes in three colours: grey, black and copper. Petra is also well sized for various spaces, with each coaster measuring at 20cm in height, 100cm in width and depth. Dimensions: W: 10 x D: 10 x H: 2 cm