I brought a ring to a jeweler to ask if the diamond was real. He used some device that beeped when touching...

Question

...diamond. What was that and what does it do exactly?

Answer 1

Electronic diamond testers work by measuring the loss of heat from a metallic probe. Diamonds are excellent conductors of heat and will draw the heat from the probe faster than simulants. An electronic diamond tester will tell you whether or not a stone is a diamond, but will tell you nothing about the quality of the stone.

Answer 2

I don't know that the device is called, but it was testing the thermal conductivity of the stone. How it works: it has a heated tip that is put against the material to be tested, then the device measures the heat lost from its tip into the material. Diamond has high thermal conductivity so it will absorb a lot of heat from the device whereas fakes will not absorb as much.

I remember my chemistry professor saying that some fake diamonds can only/best be distinguished from real diamonds by their thermal/electrical properties. Apparently there is one type of fake diamond (moissanite) that can fool the thermal conductivity test, so nothing's perfect. Also, I believe the thermal conductivity test won't work on man-made "real" diamonds which are chemically the same as Earth-made, natural diamonds... although I could be mistaken.

More info can be found here: http://www.nationaljewelerssupplies.com/diamond-moissanite-test.html

Answer 3

a really easy way to tell if a gem in a ring is a diamond is to drop it in a glass of water. because of the way light is refracted/reflected by diamonds, if the gem is a real diamond, it is completely invisible in water

Answer 4

it is a laser/light to check quality