Copper Metal from Malachite circa 4000 B.C.E.

Abstract

After the development of the field of ceramics, for Stone Age man, the smelting of copper might have represented the next designed chemical transformation of one substance into a more useful second substance. Around 6000 years ago the procedure involved heating copper ore in the presence of charcoal; we have created a laboratory experiment inspired by this idea. The experiment starts with a naturally occurring ore, malachite, essentially pure Cu2CO3(OH)2, which is readily available at modest cost in bead form from jewelry stores. Using only a Bunsen burner, a porcelain crucible, and a charcoal briquette, the experiment demonstrates two steps in the ancient processing of copper ore: roasting and reduction. The product is a shiny copper metal bead that can then be hammered, polished, and shown to be electrically conductive. The procedure requires less than three hours, uses inexpensive materials and equipment, uses no hazardous reagents, and produces essentially no hazardous waste. In addition, the student ...