The Enigma of Californian Gold

Ever since the first days of the gold fever in California, the newspapers in San Francisco showed interest in the real origin of gold from the placers that exist in the State, especially those that are in the underground mines that the ancient tertiary channels followed. The Mining and Scientific Press used to publish mining letters and debates of authorities in the scientific community that questioned accepted theories. One such article of Dr. Landsweet (1969) is representative of the general tone of the debates that took place during that time. It is said that he wrote that the whole world agreed with the belief that alluvial gold was derived in one epoch or another of filones; but seeing that the biggest piece of gold that was found is insignificant when it was compared to the nuggets that had sometimes been found in alluvial material had made it very difficult to conciliate with the belief of the experience.

Dr. Landsweet described a series of experiments in which they mixed very diluted solutions of chloride of gold and a carbon material that was used as a decomposing agent in order to obtain films of precipitated gold over the central areas of pyrite, iron, copper, antimony, galena and other metals and minerals. By using limonite, the gold deposited itself in a metallic powder form.

Therefore, Dr. Landsweet concluded that the occurrence of the biggest nuggets in deposits of gravels that had been found in beds of quartz, along with the fact that alluvial gold almost always has a great standard of fineness; it seemed to imply a different origin for both.