This folder contains correspondence and other documents relating to mining and ore milling. Included are cost estimates for refining Cornwall iron ore and an undated document in Edison's hand outlining his intent to go into the Portland cement business.

The following 4 documents were not selected: mining surveys conducted for Edison by S. G. Burn; a 7-page set of instructions for sampling ore at the Ortiz gold mine in New Mexico.

Courtesy of Thomas Edison National Historical Park.