Malachite Pseudomorph after Azurite Mexico

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 Specimens. As far as azurite crystals go these were fairly large and well formed. Before they turned to malachite. By the way the malachite is chatoyant. This specimen is from the Milpillas Mine Senora Mexico.