Brochantite is a relatively common secondary copper sulfate mineral, frequently found as pseudomorphs after malachite or azurite. Although common, sharp, well crystalized examples are not, and the now-closed Milpillas mine produced some of the finest examples in recent years. This specimen features two deep green brochantite crystals to 2 cm arranged in a V shape, with a third crystal of 1.1 cm protruding from the center of the V shape. A dynamic, aesthetic thumbnail example from the collection of Irv Brown.