Boric acid, more specifically orthoboric acid, is a compound of boron, oxygen, and hydrogen with formula BO3H3 or B(OH)3. It may also be called hydrogen borate or boracic acid. It is usually encountered as colorless crystals or a white powder, that dissolves in water, and occurs in nature as the mineral sassolite. It is a weak acid that yields various borate anions and salts, and can react with alcohols to form borate esters.