This ties in to what Marty Haske was saying about visual optics
and of course that is very important. The problem is for
jewelers or dealers who are buying a “lot” of stones or are
studying a piece that has several stones in it. For those that
have time on their hands visual optics will do. For a quick
determination, however, a machine may be the way, and obviously
a thermal unit will NOT do the trick. I have seen the material
and reported on it in JCK magazine last year (December 1996) It
does look like a diamond at first glance. Under a microscope,
“doubling” becomes visible, though you may have to look for it.
The stones sometimes have a whitish, ribbon-like inclusion. Most
stones I have seen have been off-white, leaning towards yellow.
But Jeff Hunter says that problem has been overcome and that
whiter stones will be available. GIA has prepared an extensive
report on the material in Gems and Gemology for their Fall 1997