Borate is a salt or ester of boric acid. Common borate salts include sodium metaborate, NaBO2, and sodium tetraborate, Na4B4O7. The latter also occurs naturally as borax. Borate esters include trimethyl borate , B(OCH3)3.
The mining of boron minerals is often referred to as borate mining. Various forms of borate are used as wood preservatives.