Chalcedony epimorph after Baryte

A fascinating, light powder blue mass of Chalcedony riddled with hollow epimorph cavities of former sharp bladed Baryte crystals. From Hüttenberger Erzberg in the state of Carinthia, Austria, an ancient mining district, worked mainly for iron and manganese. All surfaces of the Chalcedony are sharp and angular with a hackly texture, a term more usually reserved for metallic minerals. It appears a Baryte crystal-lined cavity, just a little larger than this specimen, was infilled with Chalcedony. At some later stage, dissolution removed the Baryte and surrounding material leaving this phantom epimorph cast of the former cavity’s interior.