Azurite/Malachite are both Copper Carbonates, and are classified as minor Copper ore minerals, which means they are formed from alterations of the original Copper ore. Azurite (the name gives it away) is a rich, azure-blue color with various lusters including lustrous and dull, while Malachite is dark to light green, with often fibrous and satin luster. Although Azurite/Malachite both have a nearly identical atomic structure, the simple change from four symmetrical oxygen atoms in a square formation in Malachite to those same four oxygen atoms in a more asymmetrical formation in Azurite results in a variation in the visible spectrum, thus green (blue + yellow) loses the yellow spectrum and becomes blue. Because of the colors, variety of formations and aesthetics, these minerals are very popular among collectors.

The crystal system for this pair of minerals is monoclinic, often forming prismatic and tabular crystals. Other forms include banded, botryoidal, massive and stalactitic.

Quality specimens of Azurite/Malachite are found throughout the world. Notable localities include China, DR Congo, Mexico, Morocco, Namibia and the USA (Arizona).