Which minerals are major commercial sources of boron?

The major commercial sources of boron are hydrated sodium borates, specifically the minerals borax, kernite, and tincalconite.1

These minerals are primarily found in arid regions, with significant deposits located in southern California, such as the Mojave Desert and Death Valley. Historically, colemanite was also a chief commercial source of boron until it was supplanted by other minerals in the 20th century. Other minerals, such as ulexite, are also associated with these evaporite deposits and contribute to the supply of boron compounds.231