Fake Diamonds in the Rough

Fake rough is being replicated so well, that it's been hard for even experts to figure out if they are real or not. There are certain naturals on the rough which make it easier to identify them. Was trying to find out if there are any references out there or tips to help differentiate between the two.

Poly Member 102564

Somewhere in your wanderings, you're going read that the little triangles or trigons (the surface appearance of trigonal trisoctahedrons) are diagnostic for diamond. Don't believe it. They can be faked. Get yourself a 50 ml plastic flask, available from any chemical supply warehouse. Fill it 3/4 full, add a few pieces of rough and measure the change in volume from adding the rough. Then, dump the rough out, weigh it on a good scale. Let's say it comes to 10 carats, exactly. That's 2 grams. And we'll say it displaced 5.5 ml of water. That would be a specific gravity around 2.7 – sure ain't diamond! Then, get yourself a piece of synthetic sapphire, maybe 10 mm across, sawed flat and semi-polished. Diamond rough will scratch it, hardly anything else will. That, and your eyes, will help.

Poly Member 1348

First, weight the product. Synthetic product will be almost twice as heavy as authentic rough diamonds. Second, all the rough I have ever seen have a "window". If not, most likely it is not properly certified with the Kimberley process and you are about to have an unpleasant business experience.

Poly Member 84388