Borax is a white, powdery mineral that people mine from dried-up lake beds and use for cleaning, pest control, and science experiments. Its chemical name is sodium borate, and it forms naturally when ancient lakes evaporate, leaving behind crusty white deposits.

You've probably seen borax in the laundry aisle at the grocery store, where people buy it to boost their detergent's cleaning power or remove stubborn stains. It's also a common ingredient in many slime recipes: when you mix a borax solution with glue, it creates those satisfying, stretchy polymers that kids love to make.

Borax has practical uses beyond fun and cleaning. Gardeners sometimes sprinkle it around plants to keep ants away, and it helps control cockroaches too. Before refrigeration existed, people used borax to preserve food, though we don't do that anymore.

The largest borax deposits in the United States are in Death Valley, California, where miners in the 1880s used twenty-mule teams to haul massive wagons of borax across the desert to the nearest railroad, a brutal 165-mile journey through scorching heat.

Borax should be handled carefully and kept away from young children. It can irritate skin and eyes and should never be eaten. If you're using it for a project, follow the directions and wash your hands afterward.