Azurite

Azurite is a beautiful deep blue copper carbonate mineral. It is most frequently associated with other copper minerals such as malachite, chrysocolla and shattuckite. These minerals form in a “copper porphyry”, where magma fluids are injected into surrounding carbonate rock such as limestone. The magma is rich in elements such as copper. The copper interacts with the carbonate in the limestone producing different minerals. The colors are typically blue or green and the color is dependent on minor differences in the copper atoms.

Azurite often forms little “blueberries”, little spheres in the rock that give the rock a spotted appearance.

Azurite in sandstone is kind of unusual. Unlike limestone, sandstone is made mostly of quartz, which has silica in it. The copper in this case uses calcite that has cemented the sandsstone together, removing the carbonate from the calcite minerals.

The various color patterns seen with azurite, chrysocolla, malachite and shattuckite are very popular together.