Azurite and Malachite, Humboldt Mine, Cochise Co., Arizona, USA
A most interesting and intriguing specimen with gemmy azurite and concentric, botryoidal growths of malachite, from an obscure Arizona silver mine. The blackish to deep red groundmass may contain cryptocrystalline alabandite (MnS), the manganoan analogue to galena, for which this mine is noted.
