"Blue Coal" is the term for a once-popular and trademarked brand of anthracite, mined by the Glen Alden Coal Company in Pennsylvania, and sprayed with a blue dye at the mine before shipping to its Northeastern U.S. markets to distinguish it from its competitors.

In the 1920s Glen Alden, and later, its subsidiary the Blue Coal Corporation, became known for its iconic “blue coal.” The anthracite coal was dyed blue by the company as a marketing ploy. Highly successful, the blue coal became synonymous with Glen Alden and high-quality anthracite.