Britannica Sources used in this answer

Where are major boron deposits found in California?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

A labeled diagram of the periodic table entry for boron shows its atomic number 5, symbol B, electron configuration, atomic weight range, and classification as a solid, weakly acidic, other nonmetal with a rhombohedral crystal structure at room temperature. — boron Properties of boron.

Major boron deposits in California are primarily located in arid regions where ancient saline lakes and volcanic activity facilitated the formation of large evaporite basins. Key locations include:12

Kramer District: Situated in the Mojave Desert, this area contains enormous stratified beds of kernite and borax.12
Searles Lake: This site is a significant source of commercial boron compounds, recovered from both borax crusts and brine.1
Death Valley: This region is noted for its deposits of colemanite, as well as other borate minerals like ulexite.12

These deposits are typically mined using open-pit techniques, where the overburden is stripped away to access the underlying borate beds. Collectively, these southern California sites provide approximately 50 percent of the world’s supply of commercial boron compounds.21