Description
This is a rare and unusual galena crystal cluster from Stari Trg mine, Trepča, Kosovo. The piece consists of multiple, highly twinned and intergrown crystals that form a star like shape around a central core. According to Gobac et al. (2012), the star-like morphology results from the oriented growth of galena octahedra along the edges of pyrrhotite crystals (epitaxial overgrowth). The overgrowth eventually completely covers the pyrrhotite, but the resulting galena crystal still reflects the outer form of the original pyrrhotite crystal. The pyrrhotite is also replaced by pyrite during this process. The pyrite after pyrrhotite pseudomorph core is visible in the bottom of the piece.
Please note there are visible fractures along the bottom of the piece where it was attached to the host rock. These fractures are from collection, and the piece is stable, even with the fractures. If you have any concerns when you get it, let us know, and we accept a return at our cost.
Reference: Željka Žigovečki Gobac, Vladimir Zebec, Snježana Mikulčić Pavlaković, Vladimir Bermanec, Posebno izdanie na Geologica Macedonica,,№ 3, 2012.
This piece is 35 X 35 X 17 mm and 72 grams.
(PDF) Star-like galena crystals from Stari Trg mine, Trepča, Kosovo (researchgate.net)