Mining sand, clay and other industrial minerals for use by industrial concerns was a solid business for over 100 years, but the explosion of unconventional drilling that has helped boost US petroleum output to levels not seen in decades opened a new and lucrative market.

US Silica is a 112-year old company that got its start supplying sand to Pennsylvania’s glass industry, but around 2008 the firm began to supply proppants to companies that were hydraulic fracturing wells in order to tap liquid and gas hydrocarbons trapped in low-porosity geologic structures like shale. Keep reading →