Composition - Lead sulfide. May contain impurities, such as silver, arsenic, antimony, and copper. Argentiferous Galena - Galena with a large silver content.
Dodecahedrons are far less common.
Also occurs massive, grainy, fibrous, platy and as veins. Care - Galena may tarnish when exposed to air and become dull in luster. Freshly cleaved specimens exhibit a strong metallic luster. Over time the luster turns more dull, but still metallic. The tarnish can be temporarily removed by scrubbing with water and mild soap.