 Beginning in the 1880s Black Diamond was a rural coal mining area, developed by the Black Diamond Coal Mining Company of California, which owned and operated the mine.The original residents were largely composed of former workers, from the company's previous coal mining operation in Nortonville, California, which primarily sold coal to the thriving new metropolis of San Francisco.A combination of low quality coal from the Nortonville mines, water intrusion into the workings there, and the discovery and economical transport of higher-quality Washington coal to San Francisco spelled the demise of Nortonville in the early 1880s.