Yes! In 2018 the US Fair Trade Commission determined that a diamond does NOT have to come out of the ground to be real. "A diamond is a mineral consisting essentially of pure carbon crystallized in the isometric system."
With the naked eye, no. With a 10x loupe, no. With specialist equipment that can detect the 415.5nm absorption spectrum caused by N3 in mined diamonds? Yes.
Absolutely! They are optically, physically, chemically and thermally the same. The only difference is they were grown in a lab instead of being dug out of the ground.
To find 1 carat of polished diamond in the ground you have to dig up 25 tons of rock, break it into smaller pieces, and search for the hidden gems. What's more, it can takes years -- decades, even -- and hundreds of millions of dollars to find one of the rare volcanic pipes that contains diamonds. Growing diamonds is much more efficient.
There are two ways a diamond gets color. The more common way is to treat the diamond after it has been cut and polished. This is fairly inexpensive, but it creates a diamond with little color variation throughout the diamond. In the view of our experts, this looks more like a colored stone than it does a natural color diamond.
The second way uses Mother Nature's recipe of exposing the diamond to various gases during the crystal growth stage. This produces a much more beautiful diamond, but it comes with a downside: just as in nature, the process is uncontrollable. More often than not, adding boron gas helps create a whiter stone, as boron negates the yellowing effects of omnipresent nitrogen. But every so often, for reasons not well understood, it turns the diamond blue. That change has been called everything from "an accident" to "a miracle of nature." Either way, the result is stunning.
Color diamonds are graded on a scale that runs from Fancy to Dark. The "best" is largely a matter of personal preference, though prices are generally higher for the darker shades.