A rare mineral that comes from Africa and some has been also found in the Empire Nevada Mine. Cornetite is a rare secondary copper mineral that is noted for its deep blue, green-blue to green color. Found in oxidation zones of copper sulfide ore bodies.
You can also see malachite just under the cornetite and if you look close with a loupe the crystals are translucent and very rich blue, like the finest of all gem silica in a dark blue you almost never see!
This is a VERY VERY nice example of cornetite. It's very seldon seen espesially cut into a cab for jewelry.
The surface of good cornetite druzy glistens with VERY tiny sparklies, a little different than a quartz drusy would sparkle.