This folder contains correspondence and other documents relating to mines and minerals to be bought, sold, surveyed, worked, or tested. Included are inquiries by Edison to various suppliers of minerals, letters concerning ores that Edison might supply, requests to have ores tested by Edison, and offers to sell mining properties and mineral products. Among the metals and minerals mentioned are cobalt, elaterite, selenium, tellurium, lithia carbonate, and pumice stone. There are also letters regarding gold mining, assaying, and the publication of Edison's opinions on these subjects in the Saturday Evening Post in January 1911. A few items pertain to Edison's technologies for the magnetic separation of ores and to inactive ore milling companies such as the Edison Ore Milling Syndicate, Ltd., and the New Jersey and Pennsylvania Concentrating Works. Among the correspondents are longtime Edison associate Edward H. Johnson, geologist Henry C. Demming, and William H. Crane, president of the American Lithia and Chemical Co. Approximately 50 percent of the documents have been selected. Most of the selected items received a significant response from Edison. The selected material also includes a sampling of letters relating to Edison's acquisition of supplies for production and experimental purposes, often for possible use in his alkaline storage battery. Other letters for which samples have been selected concern Edison's advocacy of thinly rolled nickel sheets, rather than paper made from wood-pulp, in the production of books and other printed matter—an idea publicized widely by newspapers and magazines, including the February 1911 issue of Cosmopolitan. Referrals to other vendors and letters concerning ores that Edison was not interested in purchasing have not been selected. Similar material can be found in the unselected archival folder, "Metals and Minerals." Courtesy of Thomas Edison National Historical Park.