Telling if you have a real diamond or a cubic zirconia is of obvious importance. While there are a number of different tests out there that can help put your mind at ease, one of the best tests is a diamond heat test. Why does this test work? Actually, it’s due to the unique conductive properties of natural diamonds and cubic zirconia.
Natural diamond conducts heat quite well. In fact, it is an even better conductor of heat than copper is, which makes it valuable in many industrial and commercial settings. However, cubic zirconia is an insulator, which means that it does not conduct heat very well at all.
A diamond heat test can be performed at home. In this instance, you simply breathe on the stone, as if you were going to clean it. Your breath should fog the stone with moisture. If the moisture (fog) evaporates quickly, you probably have a real diamond. However, if the stone does not clear in a short time, you likely have a cubic zirconia.
A more reliable test can be performed using heat, but it requires special tools to do it. These tests measure the amount of heat conducted by the stone in question. However, the equipment needed is rather expensive and is not likely to be something in which you need to invest. A jeweler can conduct such a test, in concert with other specific testing methods.
If you choose to conduct a diamond heat test at home, you should incorporate another test with it. You should also remember that no home testing method is foolproof and the only way to know with 100% certainty that your diamond is real is to have it appraised by a jeweler. To avoid such confusion, only purchase diamonds that come with a GIA certificate of authenticity.