Harmony BORAX Mine in Death Valley 

Borax, a group of boron minerals, originated in hot springs and volcanic vapors. In the 1870s, the borax boom led to prospectors claiming salt flats in California and Nevada. Aaron Winters discovered borax on a Death Valley salt marsh in 1881. His claims were purchased by W.T. Coleman, who built Harmony Borax Works. The famous 20-mule teams transported borax from the Amargosa Works to less torrid Shoshone. In the 1900s, miners focused on glassy veins of colemanite in the Calico Mountains. From 1928 to 1971, Death Valley borax was dormant, but the Billie Mine remains active today.
Borax has diverse uses, including ceramics, heat-resistant glass, welding, disinfectants, and preservatives in cosmetics and foods