top of page

124 mm Thomsonite, Diopside and Grossular

$ 129.99



Bumannsfjorden, Seiland, Finnmark, Norway

Size: 118x124x59 mm (1672 gr.)


Here is a huge sample of extremely rare light pink Thomsonite pseudomorph after Nepheline crystal, on a layer of Diopside/Grossular. The Diopside and the Grossular are mainly weathered.

It is a very rare combination, and my father found just a few ones like this. I have now got it proven by a lab that it is in fact Thomsonite. You can also see the mineral listed at Seiland at Mindat:

In mineralogy, a pseudomorph is a mineral or mineral compound that appears in an atypical form (crystal system), resulting from a substitution process in which the appearance and dimensions remain constant, but the original mineral is replaced by another.

Bumannsfjorden, Seiland, Finnmark, Norway

Most of the year the field where the minerals are found is covered with ice and snow, and today this area is now a part of the Seiland National Park, and collecting from this area is now strictly forbidden. So not only is this a rare material but also it will not be collected more of it.

This specimen was found in the late 1980's by my father, Gunnar Mathisen. 

Seiland 003.jpg
Seiland 002.jpg
bottom of page