A borate mineral with chemical composition Mg₃B₇O₁₃Cl. It occurs in Germany, England, and the United States, usually in bedded sedimentary deposits of anhydrite (CaSO₄), gypsum (CaSO₄ · 2H₂O), and halite (NaCl), and in potash deposits of oceanic type. The chemical composition of natural boracites varies, with Fe²⁺ or Mn²⁺ replacing part of the Mg²⁺ to yield ferroan boracite or manganoan boracite.