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Showing posts with label John I. Koivula. Show all posts
Showing posts with label John I. Koivula. Show all posts

Saturday, August 15, 2020

Reversible Twinning In Neodymium Pentaphosphate

For practising gemologists only. Neodymium pentaphosphate is a rare experimental synthetic material that shows reversible lamellar twinning under polarized light when gentle pressure is applied perpendicular to twinning planes. Take a look.


Useful link:
https://www.gia.edu/gems-gemology/spring-2020-microworld-reversible-twinning-ndp

Saturday, August 01, 2020

Unknown Inclusion In Triphane Spodumene

Raman microspectrometry wasn't able to identify the orange inclusion. This was because the crystal faces of the spodumene were etched, which interfered with the passage of the laser in spodumene. Take a look.


Useful link:
https://www.gia.edu/gems-gemology/spring-2020-microworld-unknown-inclusion-in-triphane-spodumene