First, lets clear up one misconception. Lab-grown diamonds ARE diamonds. 

They’re not simulants like cubic zirconia. Simulants just look like diamonds. Synthetic, or lab-grown diamonds, have the same chemical composition and crystal structure as natural diamonds. The difference: one grows in the earth and the other grows in a lab.

Think back to high school Chemistry class when you had to memorize the periodic table. Diamonds are made of the element carbon. When carbon is subjected to exactly the right conditions of extreme heat and pressure under the earth’s surface, a diamond can form. This formation doesn’t happen quickly or easily. It can take hundreds of millions of years. One of the reasons diamonds are so valuable is because of their rarity.

In the 1950’s scientists began experimenting with ways to speed up the process of diamond formation. They created a method which replicated the high pressure, high temperature (HPHT) environment within the earth. But this process takes place in a controlled lab environment over a few days or weeks.

How can you tell a lab-grown diamond from a natural diamond? Quite simply, YOU can’t. Even a jeweler can struggle to tell the difference. An electronic diamond tester won’t help. Both test as diamonds because they are both diamonds. Occasionally a gemologist can detect certain inclusions, graining and fluorescence under a microscope that differ between the two. The easiest way to distinguish—assuming the lab-grown stone came from a reputable dealer—is to view a tiny etching along the diamond girdle with the letters “LG” and a serial number. This would require a loupe or a microscope. To the naked eye, there is no difference.

So which should you buy? Both are beautiful. Some believe that lab-grown stones are better for the environment because we’re not digging miles into the earth to mine them. Others prefer the rarity of a stone that took millions of years to make its way to the earth’s surface. Lab-grown stones are much less expensive than natural diamonds. It’s really personal preference. I’ve recently seen more interest in lab-grown diamonds from Millenials and Gen Z’ers who are able to buy twice as big a stone for the same price.

My advice is to buy from a trusted jeweler who can walk you through the options and point out the subtle differences through a loupe or microscope. 

Just for fun, the four studs below are all diamonds of different sizes. Which one is lab-grown?