Psilomelane is manganese oxide with velvet swagger: botryoidal black surfaces banded with silver-gray, polishing to a gunmetal sheen unlike any other stone. Mexico’s Chihuahua deposits provide the classic lapidary material.Each psilomelane at GEMIC Institute is natural, certified in our Siem Reap laboratory and photographed exactly as sold. One-of-a-kind pieces; tracked worldwide shipping, 30-day inspection period.