A teal coloured copper silicate frequently found in association with malachite. Unlike malachite is it not a good ore of copper and is often simply put on the spoils heap in commercial mining. It is a secondary alteration product and is usually formed by weathering of other copper compounds. It often occurs as a psuedomorph (a chemical replacement of one mineral by another which preserves the shape of the original mineral). It is usually botryoidal and does not form crystals.