MT69AL4: Twinned crystals of Sphalerite much more individualized and well defined than usual in this deposit, with some areas replaced by Chalcopyrite, very lustrous, on matrix and with Quartz and Calcite. The back shows a crystalline contact without breakage, as evidenced by the presence of Boulangerite in good condition.
Stan Trg (Stan Terg, Stari Trg) Mine, Trepča Complex, Trepča Valley, Kosovska Mitrovica, Kosovska Mitrovica District  Kosovo (2012)

Specimen size: 4.7 × 4.3 × 2.4 cm = 1.85” × 1.69” × 0.94”

Main crystal size: 2.3 × 1.6 cm = 0.91” × 0.63”