Cave Creek Golden Reef Mine Stamp Mill
January 19, 2017
Photographer: Thomas McGuire
Summary Author: Thomas McGuire
Unlike most of the eastern U.S, climate made farming difficult in the American Southwest. Furthermore, there are relatively few navigable rivers. So many towns like Cave Creek, Arizona, were founded where mineral deposits were discovered. The Cave Creek Gold District never became a major producer. Nonetheless, mining activity grew from when gold was first discovered here in the 1870s until the early 1900s.
Minerals are separated according to their physical and chemical properties. Gold is relatively inert so it's usually found in metallic form. Its density is about 6 times the density of other rocks. So gold can be recovered from placer deposits (stream gravel) by activities such as gold panning.
Gold in bedrock is another story. An important part of gold recovery from bedrock sources is crushing the ore into small pieces. This is the objective of the stamp mill. Each of the cylindrical stamps weighs about half a ton. When they repeatedly fall on rock, they crush it into sand-sized particles and even smaller. Gold may settle into grooves below the stamps or it can be separated by panning the crushed ore. Chemical separation may use mercury or cyanide (both poisonous and environmental hazards) or other chemicals. Photo taken on September 1, 2016.