In conclusion, lab-grown diamonds do not glow in the dark. The reason for this is that diamonds, whether they are natural or lab-grown, are made up of carbon atoms that are arranged in a specific crystal structure that does not emit light.
Fluorescence is the glow you sometimes see when an object emits visible light. Some diamonds fluoresce when they are exposed to long-wave ultraviolet (UV) rays from sources like the sun. This can cause them to emit a bluish light or more rarely, a yellow or orangy light.
Just like natural diamonds, lab grown diamonds can fluoresce under UltraViolet (UV) light. This remarkable characteristic causes diamonds to glow beautiful colours or a brighter shade of white.
The phenomenon that causes a diamond to glow under black light is called fluorescence. Around 35% of diamonds grown naturally have this component in them, and 95% of them glow a bluish color when exposed to a black light.
Lab grown diamonds are chemically the same as mined diamonds, and one of the only ways to tell the difference is for a gemologist to look under a magnifier for a laser inscription on the girdle of the diamond and determine the origin.
Lab grown diamonds and mined diamonds are anatomically, chemically & physically exactly the same which means that it is very difficult to tell them apart. The truth is that jewellers and gemologists cannot tell the difference between mined and lab grown diamonds without specialised equipment.
The only way one could distinguish a lab grown diamond from a natural diamond is with the help of a microscope. Natural diamonds will have small amounts of nitrogen, whereas lab grown diamonds will not.
A fake diamond will let the black shine through, and you may even be able to read a word depending on the size of the fake stone. If your diamond is mounted, make sure you can't see through it to the mount itself — that's a very bad sign.
The Sparkle Test
Synthetic or fake stones, sparkle less than real, or mined diamonds. With light reflection, look for shades of gray. Synthetic stones, such as cubic zirconia, sparkle with more iridescent colors. Natural diamonds reflect light in more grayish hues.
A real diamond appears gray and white inside (brilliance) when held to the light and can reflect rainbow colors (fire) onto other surfaces. A fake diamond will display rainbow colors within the stone when held up to light.
In such a case, they lose their shine due to overexposure to UV light. One reason why lab-created diamonds don't lose their shine or get faded and cloudy with time is that they are created by a process called HPHT. This refers to high-pressure high-temperature.
Lab-made diamonds typically have good clarity. Like a high-quality natural diamond, lab-made diamonds won't get cloudy.
Lab grown diamonds are as real as diamonds mined from the earth. Lab grown diamonds are identical to earth mined diamonds in every way, except that they are grown in a lab. They have the same chemical, physical, and optical properties as mined diamonds and exhibit the same fire, scintillation, and sparkle.
In more than 95% of diamonds that exhibit fluorescence, the visible color is blue. While blue is by far the most common color that a diamond will fluoresce, in rare instances the color could be yellow or red as well.
A “Lab Diamond” is just like a Natural Diamond, except instead of growing in the Earth, they grow in a lab. There is no visual difference in Lab Created Diamonds vs Natural Diamonds. They sparkle the same, have the same types of color and clarity, and can come in the same sizes and shapes.
Like natural diamonds, the best color for a lab grown diamond is D color grade. It is the highest color grade available and lab diamonds in this category are completely colorless, even when examined via magnification.
Ultraviolet Light: About 30% of diamonds will glow blue under ultraviolet lights such as black light. Fake diamonds, on the other hand, will glow other colors or not at all.
Most synthetic diamonds look too good to be true all due to their extreme brilliance. Does your stone look really bright with lots of rainbow reflected colors? If so, it's most likely cubic zirconia.
Unlike natural diamonds mined from the earth, lab diamonds won't usually gain value. In fact, in recent years, their value hasn't kept up with inflation, mostly due to the increased availability of lab-grown gemstones. So, to put it simply: a lab-grown diamond isn't going to bring much, if any, return on investment.
Lab grown diamonds are known by many names: lab grown diamonds, cultured diamonds, man made diamonds, synthetic diamonds along with many others.
CVD diamonds are grown in a lab, and they have the same chemical structure as natural diamonds that are mined from the earth, so they are quite different from cubic zirconia stones, which have completely different chemical and physical structures from diamonds.
Lab-grown diamonds are purer than the stones mined naturally, because unlike mined stones, synthetic diamonds do not have any dirt or impurities ingrained in them. They also have fewer defects, and show fewer signs of strain in their crystal structure, because they are made under carefully controlled conditions.
Here's the Short Answer
Lab-created diamonds are chemically the same as natural, mined diamonds. They are more affordable, but their value likely will not hold up over time. They will also never have the same rarity, uniqueness and meaning as a natural stone that was formed over billions of years deep in the earth.
If a product is a lab-grown diamond, then the fact that it is man-made must be clearly and conspicuously stated.
If you hear that lab grown diamonds don't hold any value after purchase, then that simply isn't true. Lab grown diamonds certainly have value for their appearance and durability, and as we've mentioned they are exactly the same as natural diamonds in chemical make-up and hardness.