👉 Cyanite is a mineral that occurs as a green or blue-gray crystal with a diamond-like structure. It is often found in rocks, such as igneous and metamorphic deposits, and it has been used for thousands of years to make tools, weapons, and other objects. The name "cyanite" comes from the color of its crystals, which are usually blue or green in appearance. The mineral is named after the chemical formula of its constituent elements: C (carbon) + 2