I had a customer bring in a stone that they where told was a black diamond. I took it to a gemologist and they told me it was a “sintered black moissanite”. If you look under magnification it has all these tiny little pits in the surface. They have been wearing the stone for a few months and stopped in to ask why their stone was scratching on the table. I haven’t ever seen anything quite like it. There are scratches and more pitting on the table, but the facets edges do not have the typical abrading you see on softer stones. Is black moissanite not as stable as white moissanite?
Hi Nicole,
How did the gemologist determine it was a sintered black moissanite? Understanding what diagnostics they did would be good information to know.
Cheers!
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I was not aware of black moissanite.
A quick look in some publications provides this article: New Large Black Synthetic Moissanite as a Black Diamond Imitation | GGTL.
The description you provided does seem to match what this report indicates, however, photos of the grain/pitting would help with any possible confirmations.
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Black mossinite is definitely available. Take a look at Tom’s box of rocks on Etsy. He specializes in synthetic stones and rough of all varieties. At least you can see what is readily available.
moissinite is silicon carbide or carborundum. It’s the most common industrial abrasive. Powdered silicon carbide can be made in small or large grain sizes for grind and polishing. Very fine grained carborundum powder is sintered together using high temperatures. The grains stick together but are not melted. The pitting on the table could be from residual graining or from loose grains knocked off. The hardness of silicon carbide is 9.4.. the edges will not be scratched by usual wear and tear. Sintered powder moissanite is not a crystal. It’s a little more susceptible to wear and tear. Crystalline moissanite is synthesized using vapor deposition or HPT presses, the same process that synthetic diamonds are created. The synthesis of diamond is faster than making moissanite. So why bother with creating moissanite instead of diamond? Moissanite still cheaper than diamond. Sintered powdered carborundum is even far cheaper. .
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