A sharp example of these classic old Malachite after Azurite from South Australia. The form is preserved dramatically and really quite amazing, as one side is a sharp, clearly defined "rhomb" (you can see why they thought it was a replacement of calcite from some angles), while the opposite side has fine, intergrown faces that resemble an Azurite rosette. Certainly, Malachite after Azurite pseudos are well-known from Sir Dominick, so although both the rhombic form and the Smithsonian label both say 'Calcite' - yet we believe this is after azurite and not calcite. Likely mined in the late 1860's. Better even in person. Formerly in the famous collections of Washington Roebling and the Smithsonian.