Montebrasite (fine quality) on Albite

Item Description

Please note that this is not Amblygonite, which was a typical labelling mistake that took place with this material for many years. It turns out that true Amblygonite is actually quite rare. Both species are isostructural and are both lithium aluminum phosphates, but the difference is that Montebrasite has a hydroxide ion in its chemical formula, while Amblygonite has a fluoride ion. In terms of charge and size, the fluoride ion resembles the hydroxide ion, so it's easy to see why so many Montebrasites were labeled as Amblygonites back in the day. With that said, this is a wonderful matrix display specimen of the material. The piece features a highly lustrous, very sharp, well-formed, soft pastel yellow-green crystal of Montebrasite measuring 3.7 cm long sitting among white bladed Albite (var: Cleavelandite) matrix. Alongside the main Montebrasite is a beautiful "sidecar" crystal that is equal quality to the larger one. My favorite aspect of the piece is the luster, as it really shines and if you do a comparison online, you'll see a lot of Montebrasite specimens are rather dull with little to no luster whatsoever. The piece is a nearly a complete "floater", as it's crystallized on all sides, but I did see a point of a attachment on the back, so it's not quite 100% complete. When it comes to pegmatite gem crystals, there are tons of Beryls, Tourmalines, Topaz, etc. on the market, but fine matrix Montebrasite specimens are few and far between. A fine specimen and a must have for any fan of gem crystals, pegmatite minerals or species from Brazil. Priced in the inventory at $4,000.