A striking blue cloud was too puffy so it fell out of the sky. Curious humans sliced it up only to find it was green inside! 😮 Chrysocolla-Malachite is a combination of two Copper minerals. Copper typically forms as a sulfide, which oxidizes when exposed to water. If that water also contains carbonic acid, it dissolves the copper and forms new compounds, including green Malachite. If the copper is oxidized, Chrysocolla forms. Sometimes these two situations happen in the same spot, and so Chrysocolla and Malachite will grow next to each other or even intertwined. If the stone forms as thin layers, one mineral on top of the other, it is considered a Sedimentary rock.