This is such a cool item!!
We got them from a great cutter.
They are heated to get the opaque black appearance.
You can see into the stones a little bit but mostly you get the facets flashing back - they're so shiny!
The cut is cool too. The bottom of the stones are totally flat giving us stones with great size- and earrings that are a little longer than 3/4 of an inch.
We used top-notch round brilliant diamonds to frame them - in totally custom made, and totally solid 18kt white gold bezel settings.