Calcite (S 2d)

Calcite (S 2d) refers to a specific crystal structure of calcium carbonate, a common mineral found in rocks and shells. It typically forms in a rhombohedral shape and is notable for its clear to white appearance and its ability to refract light in unique ways, often causing a phenomenon known as double refraction. Calcite is significant in various industries, including construction (as limestone), agriculture (as lime), and even as an investment in rarer forms like decorative stones. Its presence is an indication of specific geological processes, making it important for scientists studying Earth's history.