What Makes a Diamond a Diamond
A lab-grown diamond and a mined diamond are both crystallized carbon, and there is no chemical, physical, or optical difference between them. They share the same hardness (a 10 on the Mohs scale), the same fire and brilliance, and the same crystal structure. Under a standard jeweler's loupe, they look identical — telling the two apart requires specialized lab equipment that can detect subtle growth traces left behind by how each stone formed.
How Each One Forms
Natural diamonds form roughly 90 to over 400 miles below the earth's surface, under heat and pressure conditions that exist only that deep underground, over the course of one to three billion years or more. Curiously, the diamond itself is usually far older than the event that brought it to the surface — most diamonds sit dormant in the earth's mantle for eons before a violent kimberlite eruption sweeps them upward, and most of those eruptions happened somewhere between 50 and 250 million years ago. The diamond in a ring, in other words, was already ancient by the time the volcano that delivered it even existed.
Lab-grown diamonds recreate those same growth conditions inside a controlled lab environment, using one of two processes. HPHT (High Pressure, High Temperature) places a small diamond seed in a molten metal solvent and subjects it to temperatures of roughly 1,300–1,600°C under pressures exceeding 870,000 psi. CVD (Chemical Vapor Deposition) instead places the seed in a vacuum chamber filled with carbon-rich gas, heated to around 900–1,200°C, and builds the crystal up carbon atom by atom over several weeks. CVD has become the more common method for producing gem-quality, near-colorless stones, since it offers finer control over the result — HPHT is now frequently used as a second step afterward, to treat CVD-grown diamonds and remove any residual brown tint.
Certification & Grading
Both types are graded on the same 4Cs — cut, color, clarity, and carat — by the same major labs, including IGI. The difference on paper is that a lab-grown diamond's certificate explicitly states its growth method (HPHT or CVD) and that it's laboratory grown, and the stone itself is typically laser-inscribed on the girdle with both the report number and the words "LAB GROWN," so there's never any ambiguity for insurance, resizing, or resale down the line.
Price & Value
Lab-grown diamonds typically run somewhere in the neighborhood of 80–90% less per carat than a comparable natural diamond. That gap has actually widened in recent years, as lab-grown production has scaled significantly and retail prices have fallen accordingly — which is a big part of what makes it possible to size up meaningfully in carat weight without sizing up the budget.
Worth being honest about: that same production scaling means resale value on a lab-grown diamond is currently quite low, often recovering only a fraction of the original purchase price, and natural diamonds tend to hold their value somewhat better on the secondary market by comparison. In practice, we'd steer most people away from thinking of either type as an investment — buy the piece you'll love wearing, not the one you hope to sell later.
Sustainability & Sourcing
Lab-grown diamonds skip mining entirely, and their lab origin makes the supply chain simple to trace. Most mined diamonds sold today are also certified conflict-free under the Kimberley Process, an international certification scheme established in 2003 with roughly 49 participating countries — though it's worth understanding that the Kimberley Process specifically addresses conflict financing at the point of export, not a broader guarantee covering labor practices or environmental impact. If that fuller picture matters to you specifically, a lab-grown stone removes the question altogether.
Which Should You Choose
Neither is objectively "better" — they're simply different origin stories for the same stone. If maximizing carat size on a given budget is the priority, lab-grown is the clear winner. If mined rarity and heritage matter to you personally, natural is the path. We default to certified lab-grown diamonds for custom pieces because of the value it unlocks, but we're glad to source a natural stone on request.