Laumontite

Laumontite, a hydrated calcium aluminum silicate, is a rare zeolite mineral from California, highly sought after yet uncommon in collections. This specimen features a parallel-growth pair of sharp, terminated, crystals with a creamy-yellow hue and lustrous surfaces. The finest California examples originate from this now-extinct tungsten-molybdenum mine. Laumontite specimens are notorious for disintegrating over time, but this piece has remained stable, likely due to a light coating of shellac applied for preservation. It is also possible that the Laumontite has been pseudomorphed by leonhardite, as some similar crystals have been identified as such. This is an excellent, well-preserved example of a rare mineral from a classic locality. Collected sometime between 1910 and 1950, most likely.