Home > California Borate Minerals – July 22 > MS0957 Ulexite after Borax

Ulexite after Borax - Sold

Ulexite is a complex sodium calcium borate mineral with triclinic symmetry. The name honors Georg Ludwig Ulex (1811-1883), a nineteenth century German chemist. Ulexite typically forms fine needles and fibrous masses, and specimens are rather difficult to find. This is an unusual example of ulexite forming a pseudomorph after a borax crystal. Borax dehydrates to tincalconite in air, and this example has a white powdery core of that mineral. Fine grained ulexite forms a thick porcelain like growth over the crystal cluster. An interesting pseudomorph!