Contemporary Bathroom by Casa Verde Design - Quartz is one of nature’s hardest and most abundant minerals. In fact, nearly every type of stone contains some percentage of this ubiquitous material. Manufacturers of quartz countertops (familiar brand names include Caesarstone, Cambria, Zodiaq and Silestone) add pigments, resins and, occasionally, recycled content, to a base that is about 95 percent natural stone.