Boron

Boron is a metalloid, with properties between those of metals and nonmetals. Its crystalline form is dark, hard, and brittle, and conducts electricity poorly at room temperature. In nature, boron occurs mainly in compounds called borates. Minerals such as borax and kernite are mined from deposits left by evaporating water, then refined into useful boron compounds. Producing the pure element requires further chemical processing to separate boron from other elements. Most uses involve its compounds: boron oxide helps make borosilicate glass resist sudden temperature changes, making it useful for laboratory glassware and some cookware. The element itself can be made into strong, lightweight fibers that reinforce aerospace materials.