Leading mining historian Kerby Jackson introduces us to a classic mining publication on the Gold Mining Industry in Arizona. Written in 1935, this hard to find publication includes valuable facts on the nature of metallic ore deposits. Highlighted here are the details on how ores are deposited, on the fallacy that ore deposits always increase in value with depth, primary ore zones, myths regarding the leaching of ores, facts about secondary ore enrichment, which rocks are associated with which types of metals and much more. This small booklet will be found to be of immense value to the miner who is looking to learn about hard rock mining. Note: This edition is a perfect facsimile of the original edition and is not set in a modern typeface. As such, some type characters and images might suffer from slight imperfections or minor shadows in the page background.