Azurite: the Blueberry Mineral

     Azurite is an azure blue mineral that is named for its color. Azurite is idiochromatic, that is, its color comes from its own chemical makeup and not from impurities. Perfect azurite crystals look like sword blades, but these are not quite so common and azurite is more often found in other forms like stalactites and stalagmites, crusts on top of other rocks, and sometimes botryoidal aggregations. As many of you may know the term “botryoidal” refers to a way in which crystals grow that looks like a bunch of grapes. However, I personally think that botryoidal azurite looks more like blueberries than grapes. When cut open azurite can resemble malachite, looking somewhat like a blue agate.
     Azurite and malachite are very similar. They are often found growing together and are even mentioned together in some books. This is because the two minerals have a very similar chemical makeup. Both are composed of the same kinds of atoms; they simply differ in the number of those atoms that make them up. Azurite can actually turn into malachite when it is exposed to the air or to water for extended periods of time. I have read that, like malachite, azurite can form on the surface of metallic copper, but I cannot personally vouch for this because I have never seen it happen myself. Because they are so similar azurite is sometimes called “blue malachite.” When azurite and malachite grow together they are sometimes collectively called “azurmalachite.”
     Azurite was once a prominent copper ore and is still used for this purpose today, though less extensively. Possibly the greatest use that azurite has ever served is as a paint-making material. In Europe, during the Renaissance, azurite was used as a blue pigment quite extensively, but that use came to a screeching halt during the 1600s. The reason that people stopped using azurite to make paint is because of the fact that it can turn into malachite and thereby change from being blue to being green. After a while people began to notice that the deep blue skies in some of the older paintings began to turn green! Soon after this they began to make paint out of other substances that would hold their color. Today azurite is used as a decorative stone, mainly in the area of carving, though it does serve a tiny use in jewelry. Azurite is also very popular with rock and mineral collectors. In fact, some rockhounds say that no collection is complete without azurite!
     Azurite can be found wherever copper deposits are present. Some of the best specimens can be found in such places as: China, France, Zambia, Australia, Namibia, Bolivia, Pennsylvania, Arizona, Nevada, New Mexico, New Jersey, and Michigan.
     Azurite is a common mineral, but the intensity of its deep blue color seems to render that fact unimportant to mineral collectors. After reading this post you might be able to see why azurite is such a popular mineral to collect!