Tincalconite Pseudomorph after Borax Mineral Specimen
Our specimens of tincalconite, a rare, basic hydrous sodium borate that were collected at Searles Lake, California, one of the world’s largest evaporite-mineral deposits. Searles Lake is a seasonal lake with no outlet that originated 2.5 million years ago with glacial runoff from the southern Sierra Nevada. Searles Lake, which is dry most of the year, covers 50 square miles and contains more than 25 different evaporite minerals. Over the past 140 years, Searles Lake has yielded evaporite minerals valued at $1.5 billion. Solution mining at Searles Lake remains a major industry today. The lake’s evaporite-mineral reserves are sufficient to support mining at the current rate of production for centuries to come.
The name “tincalconite,” pronounced TIN-kahl-con-ite, stems from the Sanskrit word tincal, meaning “borax,” and the Greek word konis, or “powder,” the latter alluding to the mineral’s frequently powdery form. Alternative names have included “mohavite,” “dehydrated borax,” “three-hydration borax,” and “pseudoborax.” In European mineralogical literature, tincalconite appears as tincalconit and tincalconita.