Azurite and Malachite
Azurite is similar in composition to malachite, which is also a green copper carbonate whose crystals have a lower water content. The two minerals are often found together in deposits that occur in countries such as Africa, France, Australia, Chile and the U.S.
Crystals
Azurite often occurs in stalactites with large prismatic crystals that can be translucent to opaque and range in color from light blue to royal blue. Azurite is not a hard mineral. On the scale of hardness, it only rates about a 3.5 to 4, compared to the rating of 10 for diamonds.
Other Facts
Azurite is also referred to as chessylite, blue malachite or lapis armenius. It can be degraded by acid, but not by ethanol or water. Coarsely ground azurite yields a deep blue pigment, while a finer grind will be lighter and more transparent.