| M Formula: | 3MgO•B2O3 (orthoborate) or Mg(BO2)2•8H2O (metaborate) |
| Properties: | |
| Transparent, colorless crystals or white powder. Soluble in alcohol, acetic acid, and inorganic acids; slightly soluble in water. | |
| Derivation: | |
| By heating magnesium oxide, boric anhydride. | |
| Use: | |
| Preservative, antiseptic, fungicide. | |