We are a global leader in industrial mineral supply and science. We provide 30 percent of the world’s supply of refined borates, remarkable minerals that are essential to life and to modern living. A part of the Rio Tinto Group, an international mining and resources company, we serve more than 1,000 customers in 100 countries who rely on borates to create an extraordinarily diverse range of products.

Rio Tinto Borates distinguishes itself through cutting-edge research and development; world-class safety, environmental and community practices; and a commitment to constant innovation and improvement.

  • Operates California’s largest open pit mine in Boron, California
  • One of two world-class borate deposits on planet
  • Supplies nearly half the world’s demand for industrial borates
  • Serves customers in nearly 100 countries
  • Celebrating 145 years of continuous business in California
  • Part of London-based Rio Tinto



What Are Borates?

  • Borates are minerals containing boron, the fifth element on Periodic Table.
  • Trace amounts of borates exist in rock, soil, water, plants and people.
  • Boron-containing ores are among the rarest minerals in the world.
  • They’re essential micronutrients for plants and part of a healthy human diet.
  • A variety of household and commercial products contain borates.

Our History


Borax operates California’s largest open pit mine in Boron, California – one of the richest borate deposits on the planet. While boron is present everywhere in the environment, substantial deposits of borates are relatively rare. We supply nearly half the world’s demand for refined borates, minerals essential to life and modern living.

Borax traces its roots to California’s Death Valley, where borate deposits were discovered in 1872. The twenty mule teams Borax used to haul ore out of the remote desert live on as a symbol of the company’s commitment to innovation. The current open pit in the Mojave Desert began as an underground mine in 1927, and Boron Operations was converted to a surface mine in the late 1950s. At this time extensive facilities for refining ore were built. In 1980, Borax built its boric acid plant, securing the company’s position as the world’s leading boric acid supplier.

Today, Borax is acknowledged as the world leader in borate technology, research and development. Technical support for customers, product quality, and supply reliability are the pillars of our commercial commitment. We are also committed to ensuring that our practices and products are socially, environmentally and economically sustainable.

Borax is a member of the Rio Tinto group.





Where Are We Located?

In California, Borax operates its principal mine and refinery in Boron; a refinery and shipping terminal in the Port of Los Angeles; and a trona mine in Owens Lake. Its global headquarters is in Denver, Colorado. The worldwide organization includes a laboratory facility in Suzhou, China; a distribution and packaging facility in Rotterdam, the Netherlands; a refinery and distribution facility in Coudekerque, France; a packaging and distribution facility in Nules, Spain; and sales and customer service centers around the world.