The most vital source of boron is rasorite, found in California's Mojave Desert. Turkey has extensive boron deposits, and boron is also found in the minerals borax and colemanite.
In the environment, boron is found in the form of borates. Borates are salts of boric acid, and are present in many places in nature, including coal, oceans, shale, sedimentary rocks and soils.
Boron is essential for plants, but it can be toxic to animals in large doses. Humans consume about 2 milligrams of boron each day from food, although such a trace amount is not enough to cause harm. Some boron compounds have shown promise in producing a treatment for arthritis, and further studies into its use in this area are ongoing.