Year after year the fakes are getting harder to distinguish. At Pease & Curren, although we do not claim to be gemologists, we continually upgrade our testing equipment to keep in step with the fast growing synthetic diamond market.
It used to be we could “frost” the stones. Frosting is a chemical process during which a stone “reacts” and turns a frosted white color if it not a diamond. This has worked well up until recent times.
The properties of Moissanite are similar to that of a diamond that most diamond testers are fooled. Moissanite’s density is so close to that of a diamond it is taken for a diamond on many occasions. We now have a Moissanite tester in house although we generally are asked to sort frosted, clear and colored only.
Synthetic Diamonds correspond closely to natural diamonds. So much so they cannot be identified from the thermo tester.
In addition, Synthetic diamonds are becoming more popular, we find ourselves consistently training our personnel to properly identify synthetic fakes. Here are some tips we give to our customers:
- A synthetic diamond, sometimes called a lab grown diamond usually has an inscription on the girdle of the stone- usually of the grower’s logo.
- Sometimes a synthetic diamond displays uneven coloration. If you transmit light through it you will sometimes see a pattern.
- It may have a metallic luster.
- It may be attracted to a magnet.
- After you use a ultraviolet fluorescence lamp to identify, a persistent fluorescence will remain after the lamp is shut off.
A real diamond:
- Shows a slight or distinctive strain pattern. This is because of how it is developed over the many years of growth.
- A diamond is flawed, it has inclusions. The thing is the flaws are sometimes hard to find in melee. A larger diamond is easier.
Source: The Gemological Institute of America (GIA) has developed ways to identify these diamonds. See the GIA article which includes a chart.