Biotite vs Phlogopite
Micas are the quiet workhorses of the mineral world, hiding inside granites, sparkling in schists, and stabilizing the recipes of everything from asphalt shingles to high-temperature gaskets. Two of the most commercially relevant species—biotite and phlogopite—share a sheet-silicate backbone yet diverge sharply in chemistry, stability, and market value. Understanding the differences is not academic trivia;…