Antlerite, copper sulfate hydroxide, ranges in color from emerald to dark green. Formed from the oxidation of copper ore minerals, it was once thought to be a rare mineral. It was discovered to be the chief ore at the Chuquicamata copper mines in Chile, and since then its presence has been confirmed at several other copper mines around the world.

This stone is useful in enhancing a connection between the heart and mind. This in turn helps to provide an unbiased evaluation of feelings and thoughts. It may also be used to stimulate the thought processes and mental clarity.