Probertite (rare - Type Locality) Cook Coll.

Item Description

Probertite is a rare hydrated borate with sodium and calcium and this, the famous U.S Borax Mine, is the Type Locality. Striking intergrown, 3-dimensional radial sprays of vitreous, translucent probertite lathes, to 4.0 cm, comprise this dramatically sculptural large two-sided specimen. Ex Bill and Anne Cook Collection No. 6655 and comes with a 1989 35 mm photographic slide of part of the specimen. This is an outstanding and artistic, rare large example of this diverging style of rare probertite from the Type Locality. Large specimens of these old rare species are really hard to come by, and no more have come out in decades and then some. Esoteric, but interesting and weirdly beautiful! Valued $2000-2500