Malachite

Malachite, a mineral composed of copper carbonate hydroxide, exhibits an opaque, green-banded appearance. Its crystalline structure aligns with the monoclinic crystal system, and it commonly takes the form of botryoidal, fibrous, or stalagmitic masses.

Found in fractures and deep underground spaces, malachite's formation is facilitated by the interaction of the water table and hydrothermal fluids, allowing for chemical precipitation. While individual crystals are infrequent, they may present as slender to acicular prisms. Additionally, pseudomorphs, resembling more tabular or blocky azurite crystals, can also occur.