Laboratory-grown diamonds, quoted beside the natural stone.

It is a diamond, and it is not a simulant. Cubic zirconia and moissanite are different materials that look approximately like diamond; a laboratory-grown diamond is crystallized carbon, the same mineral, and GIA describes it as having essentially the same chemical, physical and optical properties as a natural one. The honest qualifier is GIA’s own: the growth environment differs, so the properties are nearly the same rather than identical in every respect. It is still a laboratory-grown diamond, and we will describe it that way on the invoice, on the appraisal and out loud.

No, and neither could we. Face-up, at any normal distance, there is nothing to see. Separating a laboratory-grown stone from a natural one takes a gemological laboratory with spectroscopic equipment — a loupe, a jeweler’s eye and a pocket tester will all fail. That is precisely why we will not sell either one without its report.

Expect materially less than a natural stone, and plan on not selling it. Wholesale laboratory-grown prices have fallen sharply for several years and are still falling, so a stone you resell is competing against a brand-new equivalent that costs less than yours did. Natural diamonds are not an investment either — the resale market is well below retail there too — but the direction of travel is different, and you deserve to hear that before you spend the money rather than after.

Nothing is wrong with it. Supply is the whole answer: a grower can produce more, on demand, in weeks, and growing capacity has expanded far faster than demand has. Cut, polish and finishing are done by the same cutters, to the same standards, and a badly cut laboratory-grown stone is just as disappointing as a badly cut natural one. Cut quality is where we will push you hardest, in both verticals.

Less than the internet suggests, but it is worth knowing. CVD stones are grown from a carbon-bearing gas onto a seed and are sometimes treated after growth to improve color; HPHT stones are grown under enormous pressure and heat and can carry a faint tint or metallic inclusions from the growth flux. Both routes produce excellent stones and both produce poor ones. Judge the finished stone and the report, not the method — but ask, and we will tell you the method and whether the color is as-grown.

All three are credible and each does something slightly differently. GIA rates colorless laboratory-grown stones as Premium or Standard rather than issuing a letter grade. IGI grades on the familiar 4Cs scale and is the most common report on laboratory-grown stones in the market. GCAL grades on the 4Cs and adds measured light-performance data. What matters more than the letterhead is that the report is for the stone in front of you: check that the inscribed number on the girdle matches the report you were handed.

They will insure and appraise it, at its own market value, which is lower than the natural equivalent. Do not let anyone schedule it without noting that it is laboratory-grown: an appraisal that overstates origin is a problem at claim time, not at purchase time. The written appraisal we supply states origin, growth method and treatment.

We are not going to make that argument for you. Growing a diamond takes a great deal of energy and the footprint depends entirely on the grid the reactor runs on; responsible mining supports whole regional economies and irresponsible mining has done real harm. Anyone selling you certainty on this question is selling you certainty they do not have. We will tell you which grower a stone came from and what they publish about it, and let you weigh it.