yellow boy
n.— «The mine drainage sediment—commonly called “yellow boy”—is, essentially, iron hydroxide, or rust. The problem is that the pollutant oozes out of mine areas, contaminating waterways and shutting down most aquatic life.» —“Bucknell Professor Paints a Bright Picture With ‘Yellow Boy’; Carl Kirby Drives Home Alternative for Acid Mine Drainage – Enviro-Friendly Paint” in Lewisburg, Pennsylvania AScribe Sept. 21, 2007. (source: Double-Tongued Dictionary)