prehistoric age

…pyrite have been found in prehistoric burial mounds, which suggests their use as a means of producing fire. Wheel-lock guns, in which a spring-driven serrated wheel rotated against a piece of pyrite, were used before development of the flintlock. Pure pyrite (FeS₂) contains 46.67 percent iron and 53.33 percent sulfur

3 million years ago; geologically, this is the middle of the Pliocene Epoch (about 5.3 million to 2.6 million years ago). The Pliocene was succeeded by the Pleistocene Epoch (2.6 million to 11,700 years ago), which terminated with the recession of the last glaciers, when it was…

…usually from the ancient or prehistoric era, though it continued to be practiced in some areas of Africa during the 19th century and possibly later. Rock art includes pictographs (drawings or paintings), petroglyphs (carvings or inscriptions), engravings (incised motifs), petroforms (rocks laid out in patterns), and geoglyphs (ground drawings). The…