COMPANY: Green Diamond Sand Products LOCATION: 500 E. Sixth Ave., Riddle PHILOSOPHY: A family business that is striving to be one of the largest industrial minerals companies in the U.S. HISTORY: Tom Marhar established Green Diamond Sand Products in 1954 at its present location. The company focused on the abrasive market, specifically providing product for sand blasting. At that time, there was a big demand for sand to blast paint and rust off ships while they were in West Coast ports for maintenance. In the mid-1970s, Marhar sold Green Diamond to Lone Star Industries, a company based in California. In …