Malachite is a banded green opaque copper carbonate mineral that forms naturally in botryoidal clusters that look like a small bunch of grapes. Botryoidal malachite is similar to a pearl in the sense that it forms radially around a nuclei such as a piece of sand or dust. As layers of malachite material form around the nuclei it forms a sphere, and when these spheres grow together it results in the botryoidal cluster that we see in raw form malachite specimens. Malachite shows a 3.5 - 4 on the Mohs Hardness Scale, and is quite heavy with a specific gravity of approx. 3.8 g/cm2.