Formel: (Na,K)3(Ca,Na)(Al3Si3O12)(SO4,S,Cl) = Feldspathoid
Colourless, greenishblue, blue
Hardness: 5,5-6
Density: 2,44-2,5
Refractive Index: 1,494-1,509
Crystal System: isometric

Hauyn (pronounced Hau-iin) is a mineral from the group of feldspathoids.


It´s origin is next to a few Afghan specimens in gem quality only in the volcanic Eifel.
And in what a quality! Hauyne from the Eifel are the benchmark for blue gemstones - highest color saturation (saturation) in both the very pure blue tones, as well as 
bright greenish-blue stones. Bright electric or neon blue over cornflower blue to the finest royal blue.
The color intensifies with increasing sulfur content. Lighter colored stones show a yellow fluorescence in the long-wave UV light.

Unfortunately, the gemstones that were ejected about 11,000 years ago at the outbreak of the Laacher volcano are stingy - and that is reflected 
in the price. Stones from 0,20 ct in the best quality are very rare. From 0.5 ct and above 1 ct extreme to extremely rare. Hauyn is a light mineral - a 
0.25 ct stone would be as much as 0.40 ct at the same size as sapphire - hence relatively high carat prices in addition to rarity.

A commercial mining of this gem never took place. In the best locality "In den Dellen" pumice is mined - Hobby and semi-professional 
collectors could search tolerated by the oweners of the newly arrived material. Unfortunately, this option no longer exists.

Hauyne is popular despite its low hardness for jewelry purposes due to its bright color.
For collectors one of the most valuable and important rarities - highest prices are achieved especially in China, Japan and the USA.

Hauyn can be confused with blue apatite and blue lazurite from Brazil. Even fine Afghanites can be equal to medium qualities. But all are dichrostic 
and easy to identify.

More difficult is blue glass. Extremely rare neon blue cobalt spinel from Vietnam has a higher refraction of light and often shows red 
reflexes (dispersion - only red and blue are not absorbed).

Since Hauyn is next to amber the German gem you will find our Hauyne among the european gemstone and rarities. Our larger stones from 0.20 ct are unique pieces 
and difficult or impossible to recover.

Just have a look at our European Gems category:



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