Malachite after Azurite w/ Azurite & Bayldonite (Kay Robertson Coll.)

Item Description

An old-time, very fine and aesthetic two-sided combination miniature crust from renowned Tsumeb. The sculptural undulating front is composed entirely of velvet malachite that has pseudomorphed small blocky azurite crystals. Many of the pseudos, have in turn, been coated by a secondary overgrowth of azurite, adding much color and contrast. The back is strikingly different! Here glorious electric-blue azurite microcrystals are starkly contrasted by yellow-green bayldonite! Bayldonite is an uncommon Pb-Cu arsenate, for which Tsumeb is famous for. Very choice and rare old combination material, probably from the Upper Oxidized Zone. Ex Kay Robertson Collection # 5159 and acquired in the mid-1960s. Kay is a prominent California collector, who specialized in European classics (see the article in the March-April, 2007 Mineralogical Record).