Galena, also known as galenite or lead-glance, is a natural mineral composed of lead sulfide (PbS). It is the most important ore of lead and deposits are found worldwide. It occurs as dull grey to silvery grey cubes or octahedral crystals, sometimes with skeletal surface as seen in this specimen. Its crystal symmetry is isometric hexoctahedral. This specimen is from a mining area near Madan, Bulgaria, actual width is 15 cm