Home > American Minerals – August 22 > MS1405 Benstonite

Benstonite - Sold

Benstonite is a rare calcium barium magnesium carbonate. The mineral name honors Orlando J. Benston (1901-1966), economic geologist at the National Lead Company, Malvern, Arkansas, who took notice of the unusual mineral. Lippmann (1961) announced the mineral discovery in Naturwissenschaften, a premier science journal. The following year, Lippmann (1962) provided a complete description of the species.

The southern Illinois fluorite district, so famous for its fluorite specimens, also produces the best of species for benstonite. This example shows benstonite forming parallel aggregates of discoidal crystals grown epitaxially on calcite crystals. The individual benstonite crystals average 4-5 mm across, and group themselves into 2.5 cm long pagoda-like aggregates. This is a rich specimen of the mineral with minor calcite matrix. Formerly in the Vic Hoffmann collection. This locality is now closed, and this material was never common at the mine. Fluorescent.