This folder contains correspondence relating to mines and minerals to be bought, sold, surveyed, worked, or tested, as well as other documents about mining-related topics. Among the items for 1918 is a letter from R. W. Walker expressing regret for a pamphlet he had written many years earlier satirizing Edison's search for cobalt. Also included is correspondence with Lt. Cdr. Charles Boone of the Naval Overseas Transportation Service about the use of iron ore for ship ballast. In addition, there is a letter of recommendation written by Edison on behalf of mining engineer Harry H. Miller, a cousin of Mina Miller Edison.

Approximately 50 percent of the documents have been selected. The unselected material includes unsolicited propositions and general inquiries, most of which received routine replies.