A rare and showy pseudomorph of lustrous, striated, azure-blue azurite after a large chalcostibite crystal nicely set in matrix from a MOST UNCOMMON locality - Rar-el-Anz, Morocco. Chalcostibite is an uncommon sulfosalt. This pseudo is REALLY GOOD and is nicely terminated. Seldom available on the market from this locality in this quality. The replacement is skin-deep, with a remaining chalcostibite core you can see from below, and by heft..