Scapolite
Posted by: macadmin on 04.22.2020 | Filed under:

Scapolite

Specimen # 100565
Mineral: Scapolite
Location: Kiran, Kokcha Valley, Badakhshan, Afghanistan
Size: 3.5 x 3.2 x 2.7 cm
Specimen # 100565
Mineral: Scapolite
Location: Kiran, Kokcha Valley, Badakhshan, Afghanistan
Size: 3.5 x 3.2 x 2.7 cm

Description

This is an amazing doubly-terminated scapolite crystal from Sar-e-Sang. The underlying scapolite itself is colourless, translucent and vitreous, but it is coated almost entirely with a thin grey veneer of an unconfirmed mineralized material that is not lustrous. What is most remarkable about this specimen is the sharp morphology of this complete floater scapolite – this is quite rare for scapolite.

Close inspection of this piece reveals a couple of spots where the veneer is missing, and what is interesting is that under magnification one can see a bit of hollowing, and the underlying scapolite looks to have become etched either as, or after, the veneer was deposited. In other words the veneer preserves the perfect morphology, but the crystal might not have appeared this incredibly sharp if not for the veneer. I also note that with magnification it seems possible to me that the veneer might be orthoclase – we have seen orthoclase as partial to complete pseudomorphs of Sar-e-Sang scapolites and there are small spots of texture on this piece that look similar to the surface texture of those specimens.

In excellent condition – one damaged spot, as photographed (one wold display out of view) otherwise no damage.

Although all Sar-e-Sang scapolite group specimens tested have been shown to be marialite (as of the publication of T. Moore and R.Woodside’s excellent Mineralogical Record article on Sar-e-Sang, in April-May, 2014), and so it is quite likely that this is marialite, this specimen has not been tested, so I have used the group name “scapolite”.


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