Hauyne Info

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Hauyne is one of the most sought after gems because of its rarity and incredible color. Hauyne ("haüyne" or "hauynite"), a member of the sodalite group of minerals, was named after the French mineralogist René-Just Haüy (1743-1822). It was first described in 1807 (Brunn and Neergard), from crystals at the Mount Somma / Vesuvius volcano in Italy. Hauyne shows a spectacular, unique, electric blue color which is caused by traces of Fe3+. Other trace elements are Mg, K, and C.

Formation and Resources

Hauyne in Pumice *
Hauyne was formed in basic (silica-under-saturated, alkaline) magmatic rocks. In course of explosive, volcanic eruptions it was blown out. The fallout contained ashes, pumice, tuff, and scoria.
All worthy, facet grade, gemmy hauyne is found only in the ashes and pumice layers which cover the Laacher Lake region (Eifel Mountains / Germany) in thick layers.
The best resources are located in the surroundings of the towns of Mendig and Nickenich (see map). Although small hauyne can still be found everywhere in the Laacher Lake region, only a few pits remain where one can find better gemstones. Because of the potential dangers in a pit a search permission of the owner is required.
The best source for hauyne is the commercial pit "In den Dellen" near Nickenich town. Here all shades of hauyne's blue can be found, up to that incredible find of a facetable 5 ct stone.
* Photo by kind permission of Peter Kohorst, finder of this stone and ©.


Although hauyne's type locality is the Mount Somma / Vesuvius in Italy, the location of real gemmy, vitreous hauyne is attributed to the neon-blue stones from the Eifel mountains in Germany. International sources state that hauyne can be found also in white, gray, yellow, violet, green or red. If such a color would appear, it would be extremely rare, and we would be delighted to show a photo. Hauyne in pumice is usually lighter and smaller (1 - 2 mm) than hauyne in basaltic lapilli which is darker and usually larger (< 5 mm). The most sought-after color is an electric, perfect blue, not too light and not too dark.


Usually hauyne crystals are found as very small (approximately 1 - 2 mm) pieces, and crystals over 5 mm are extremely difficult to obtain. Specimens from the Eifel mountains are amorphous but often gem grade grains. Hauyne rarely occurs as individual crystals. Usually they are typically grown together with other minerals.
Hauyne crystals can be opaque to transparent. Of course the best qualities are transparent. The less inclusions the better. Incredibly high prices per carat are paid for neon-blue, clean and large stones. Hauyne crystals are very difficult to facet because of its three-directional perfect cleavage. Its fragility and size limitations cause the high value of a larger, clean, faceted hauyne. Today clean, faceted hauyne is as expensive as the most valuable other gemstones.
Its value will surely increase because the few German pits will not exist for a longer time, and hauyne will become something like a "relic". The main reason is that more and more old Eifel Mountains volcanoes will be included in German nature reserves.

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