Calcite is a calcium carbonate mineral with the chemical formula CaCO₃. It is one of the most common minerals on Earth and can form in a variety of colors, including white, yellow, green, blue, orange, and pink, depending on impurities. Calcite can occur in a variety of crystal forms, including rhombohedral, prismatic, and tabular. It has a Mohs hardness of 3, making it relatively soft and often used in ornamental carvings, decorative objects, and jewelry. Calcite is widely found in sedimentary rocks like limestone and marble and is abundant in locations such as Mexico, the United States, and the UK.