This pyrargyrite is from Fresnillo in the Mun. de Fresnillo, Zacatecas, Mexico. This locale contains 50 different mineral species including pyrargyrite. It is a silver sulfide that conatains the elements Ag, Sb, and S. This specimen is an arrow head shaped piece with intact and complete pyrargyrite crystals on all surfaces including the perimeter. They have a bright, sub-metallic, luster and a brownish-black color. Under bright light and magnification you can see the red translucency of some of the crystals that lead miners to call it “Ruby Silver”. Photo 5 is of the reverse side. This is a thumbnail sized piece and it measures 18 x 13 x 5 mm.