Azurite is a copper carbonate mineral found in the oxidation zones of copper deposits and is considered a secondary ore of copper. Color ranges from light to dark blue, with medium to dark blue being more common. The intensity of its hues is what makes azurite a popular collector's stone. Azurite is commonly found in conjunction with malachite, a green copper carbonate mineral into which it slowly morphs. A mix of the two minerals is known as azurmalachite. Azurite is soft (3.5 on Mohs' scale) and opaque. When used in jewelry, it is usually seen in the form of cabochons or beads.