How to test diamond classification?

Question

differentiate diamonds to simulants and synthetic

Answer 1

The honest answer is that you can't. There are testing tools available on the market which will differentiate between diamond and most of its various simulants. These fall into two categories, first thermal probes which detect how quickly the stone conducts heat, these are cheap and quite effective but have distinct limitations. The second type are known as reflectometers which measure the reflectance of a polished stone and convert this number into a refractive index but once again these instruments have many failings in spite of what the makers would have you believe.

Without a fully equipped laboratory and an experienced gemmologist to use it there is absolutely no way you can detect if a diamond is natural or man made.

To sum up buying an inexpensive thermal tester is not a bad idea to do quick tests on stones at, for example. an antique market. Reflectometers, despite the claime made for them are absolutely not worth the cost. All in all your best bet is to take your stone to a reputable laboratory and get a proper certificate. This will avoid mistakes and, in the long run, save you money.

I hope this helps a little.

Answer 2

Use a diamond tester, I am not joking!

Diamond Testers are electronic instruments with a fine tipped probe that contact the stone and convert the level of thermal conductivity into a positive or negative test for Diamond.  Diamond has very high thermal conductivity, exceeded in gemstones only by Synthetic Moissanite, so a Diamond Tester is able to rule out all other simulants such as Cubic Zirconia, YAG, GGG, etc, and the Diamond Nite model rules out Moissanite as well.