Synthetic diamonds are man-made diamonds which are created in a laboratory- they are not imitations. Synthetic diamonds are also referred to as "created" or "lab grown." They have the same hardness, luster, and refractive qualities as natural diamonds. Most importantly, synthetic diamonds and natural diamonds are both made of crystallized carbon. They can be made under high pressure, high temperature or via chemical vapor deposition.
HPHT Synthetic Diamonds:
With this procedure, carbon is dissolved in a molten metallic solvent under extreme pressure and temperatures and then allowed to crystallize for a few days.
Chemical Vapor Deposition (CVD) Synthetic Diamonds:
Diamonds are produced at low pressures by placing small amounts of synthetic diamond seed crystals in an environment containing carbon gases. These gas molecules later decompose and the carbon atoms are deposited on the seed crystals where they eventually grow into diamond crystals.
The only major differences between synthetic diamonds and natural diamonds are the following:
- Synthetic diamonds cost less than natural diamonds
- Synthetic diamonds take less than a week to grow in a lab while natural diamonds take millions of years to form
- Natural diamonds hold more emotional value than synthetic diamonds
How to detect a synthetic diamond
Usually, jewelers try to pass off synthetic diamonds as natural diamonds so it's important to be able to identify certain characteristics in synthetic diamonds that will help you to be a smarter jewelry buyer.
Synthetic diamonds tend to have metallic inclusions which look similar to the tiny dark spots found inside of natural diamonds. These metallic inclusions are the result of tiny amounts of the molten mixture used to grow the diamonds being trapped inside of the crystals during the HPHT procedure. The use of magnification makes it easier to detect these tiny metallic inclusions.
Since synthetic diamonds tend to have metallic inclusions, they are also attracted to and repelled by magnets. If you're diamond is attracted to a magnet, then it's most likely a synthetic diamond.
Synthetic diamonds also have surface graining which are unique raised or indented patterns found on the surface of the diamond. The surface graining appears like faint lines across the surface of the facets of the stone. It's easier to see these lines when the light is reflected off the top surface of the stone. You can detect these lines with magnification.
Synthetic diamonds also have a distinctive color pattern which can be visible under ultraviolet light or when immersed inside of methylene iodide. The uneven coloration that these diamonds have is referred to as color zoning. Natural diamonds also have this same coloration but the patterns of the colors are different.
Synthetic diamonds also have a distinctive ultraviolet fluorescence which is unevenly distributed and colorless synthetic diamonds exhibit a pronounced glow known as phosphorescence.
You can also detect synthetic diamonds by using X-rays, fluorescence, chemical analysis or infrared spectroscopy.