Bindheimite and Malachite ps. after Bournonite

Bindheimite is a hydrous lead antimony oxide produced from the alteration of other ores and is a species still under investigation in terms of better defining its range in composition and structure. It is however a fascinating species and is famous from the Hüttenberg mining district in Carinthia, Austria, for replacing Bournonite, the species often referred to as cogwheel ore. This superb large miniature is composed of several sharp pseudomorphs of Bindheimite after Bournonite, with overgrowths and inclusions of bright lime-green Malachite. The Bournonite pseudomorphs range from about 1.5 to over 4 cm long and occur as blocky, well-defined crystals, still perfectly showing their cogwheel characteristics. The nature of Bindheimite is to form mottled lime-green, lemon-green and orange-tan surfaces, probably a result of the piecemeal atomic replacement of the Bournonite structure. A superb example and pseudomorph from Hüttenberg in Austria.