This folder contains correspondence and other documents relating to mines and ores to be bought, sold, worked, or tested. Many of the letters were written in response to reports of Edison's interest in developing a separation process for gold ore. Most of the selected items received a significant response from Edison.

Approximately 40 percent of the documents have been selected. Some of the unselected letters contain marginal notes by Edison requesting samples of ores or noting that the mine was unsuitable.

Courtesy of Thomas Edison National Historical Park.