Extremely large recrystallized gem sphalerite fragment from the typical cemented pocket breccias that were often found at the bottom of large geodes in this famous Spanish mine. The crystal has complex surface features with differential luster depending on the faces expressed. Also it is worth noting that the internal purity of the piece is quite apparent just by the way the light passes through with no apparent cracks or imperfections. So definitely an interesting piece both for collectors and cutters.