Malachite and Azurite are both simple Copper carbonates. Azurite occurs as a secondary mineral in the oxidized zones of copper deposits. Where as Malachite occurs as an alteration product in the oxidized zones of copper deposits. They are chemical twins. The only differences is that Azurite holds less water than Malachite. Azurite and Malachite are often mixed together and make great looking cabochons. This specimen has a lot of pure malachite bubbles on either end. It also has some basalt chunks covered with malachite. You can see the blocky forms on the front side and back side pictures. The specimen is from Zaire, Africa. It's not in perfect condition. But it's in pretty good shape and sure has some interesting shapes and forms.