A 27-element emission spectrographic analysis of “inclusion-free” fragments of an 0.885 carat type II colorless Arkansas diamond, previously crushed for a mass spectrographic analysis of occluded gas, showed detectable traces of Na, Ca, A1 and Si. XRD and chemical analyses of a thin (<2/μm), lustrous, black, opaque, totally-enclosed inclusion lying on (111) of the same diamond showed it to be amorphous and, in decreasing order of abundance, heterogeneously composed mainly of C, Fe, S, and Ni. It is speculated that the black material represents epigenetic carbonization of diamond on (111) by included gas and decomposition products of iron sulfide and iron nickel sulfide inclusions.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not have access to this content, please speak to your institutional administrator if you feel you should have access.