Amblygonite / Montebrasite (superb doubly-terminated crystal) (ex Eric Asselborn Collection)

Item Description

For reference, this specimen came labeled as Amblygonite, but as we've seen in recent years, this has turned out to be a rather rare mineral, and the vast majority of the "Amblygonites" from Brazil are in fact Montebrasite. Because it cannot be identified visually, it will need XRD to know for sure. With that said, it's an exceptionally FINE quality example regardless of species. The crystal is about as GLASSY and GEMMY as anything I've seen from Brazil, and if you do a comparison online, you'll see a lot of Amblygonite / Montebrasite are rather dull with little to no luster whatsoever. There are good sized sections of the crystal which are WATER CLEAR internally, and the highly reflective almost "wet" luster on the crystal faces makes it shine. The piece is a nearly a complete "floater", as it's doubly-terminated and crystallized on all sides, but I can see a tiny point of a attachment near the center edge. It has a somewhat "hourglass" or "bow tie" shape, and is notably tabular, which is not commonly seen in this material in my experience. When it comes to gem crystals, there are tons of Beryls, Tourmalines, Topaz, etc. on the market, but when was the last time you saw a crystal of Amblygonite / Montebrasite of such a high caliber? A world-class specimen and a must have for any fan of gem crystals, pegmatite minerals or species from Brazil. Priced in the inventory at $4,500. Specimen weight is 6.8 grams. From the worldwide collection of Eric Asselborn (specimen #A221).