Rare Galena Crystal Cluster with Six-Sided Crystals and Bulls-Eye Concentric Core from Trepca Mines, Kosovo (Copy)
This is a rare and unusual galena crystal cluster from Stari Trg mine, Trepča, Kosovo. The piece consists of multiple intergrown and twinned six-sided crystals that form around a central core. The core is a bullseye-like concentric structure that has galena at the center, surrounded by a layer of tan siderite (?), with another concentric layer of coarser siderite or aragonite(?), surrounded by a layer of sphalerite, which is finally overgrown by the six-sided galena crystals.
Gobac et al. (2012), described the oriented growth of galena octahedra along the edges of pyrrhotite crystals (epitaxial overgrowth), with the overgrowth of Galena eventually completely covering the pyrrhotite, but we have not seen anything in the literature describing a piece with a core structure of the complexity seen in this piece.
Reference: Željka Žigovečki Gobac, Vladimir Zebec, Snježana Mikulčić Pavlaković, Vladimir Bermanec, Posebno izdanie na Geologica Macedonica,,№ 3, 2012.
This piece is 50 X 45 X 40 mm and 338 grams.
(PDF) Star-like galena crystals from Stari Trg mine, Trepča, Kosovo (researchgate.net)
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 six-sided 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 somewhat reflects the outer form of the original pyrrhotite crystal. The pyrrhotite is also replaced by pyrite during this process.
This is piece is a stacked double cluster, with one crystal cluster stacked on the remains of a second crystal cluster. The lower cluster was broken during collection. The pyrite after pyrrhotite pseudomorph core is visible in the bottom portion of both layers.
Please note there are visible fractures along the plane of attachment between the two stacked crystal clusters which are also from collection. This 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 42 X 40 X 25 mm and 102 grams.
(PDF) Star-like galena crystals from Stari Trg mine, Trepča, Kosovo (researchgate.net)
