A fascinating Malachite slice displaying very well defined, thin, concentric bands of alternating rich dark green and medium green layers. This isn't just a simple slice of a Malachite stalactite/stalagmite cone showing uncomplicated concentric layering, this piece must have been cut from two juxtaposed cones that each had a double nucleus from which to grow as the two are oriented at right angles to one another. Each has a pair of adjacent nuclei with their own independent layers that slowly transition into concentric layers that are common. The piece is polished on both sides and the surfaces aren't completely even suggesting these were probably hand-polished on-site near the mine, adding some extra character to an already captivating piece! Aside from having one of my favorite names in the mining and mineral collecting realm, the Star of the Congo Mine has largely been an intermittent, artisanally mined specimen producer that has yielded some great secondary copper minerals.