Shifting fancies: The evolution of the lab-grown diamond
May 3, 2024
By Duncan Parker
Rough and cut lab-grown diamonds from the 1990s to 2023, 0.15 to 1.98 carats. Photos courtesy Dupuis Auctioneers
“Great…was the consternation and the turmoil when concrete evidence…showed that man’s restless efforts to bridle nature [to grow commercial quantities of synthetic, or lab-grown gems]…were not in vain, and congresses of the high-priests of jewellery were hastily convened to ban such unrighteous products, with what ultimate success remains to be seen.”
~G.F. Herbert Smith, Gemstones (1912)
"Lab-grown sapphires and rubies have been available for more than a century, and emerald has been grown in labs for 90 years. Upon this initial introduction of synthetic gems in the jewellery market, jewellers and dealers worldwide were convinced the new stones spelt the end of their industry. Yet, in our current market, most lab-grown gems are little-known, poor cousins to natural stones—widely available, rarely promoted, largely seen in “family rings” and the like. These days, consumers have very little awareness of lab-grown sapphire, emerald, ruby, or others, but all have heard of lab-grown diamonds.
As diamonds continue to be a mainstay of the jewellery market, consumers are actively asking for lab-grown diamonds. Price point is a main driver for demand, and a lab-grown diamond is often a small fraction of the price of an equivalent natural stone. The beauty of a diamond mesmerizes and fascinates, never ceasing to captivate the wearer, but is the lab-grown gem still a valued alternative?
Antique bracelet with old cut natural diamonds.
The original lab-grown diamonds
The gemmological world uses the word “synthetic” with a very clear definition, meaning a manufactured material that has the same chemical, physical and optical properties as its natural counterpart. The word “synthetic” means something specific to a gemmologist, but to a consumer, it simply refers to a manufactured object. Like polyester instead of silk—something that may appear similar but is not the same material.
Since the introduction of widely available lab-grown diamonds, the word “synthetic” has disappeared and has been replaced by “lab-grown.” The term is actually clearer: “lab-grown” means something grown by people rather than something found in nature.
What we now refer to as “lab-grown” diamonds have been produced since 1954, when the General Electric Company (GE) announced success in a repeatable high-pressure and high-temperature (HPHT) process to grow “synthetic diamonds,” as they were known at the time. These original lab-grown diamonds were small and intended for industrial purposes, such as abrasives. However, by 1970, GE announced they were able to grow gem-quality diamonds in their presses. By the 1990s, gem-quality synthetic diamonds were trickling into the market, though purchasers were not always informed. These diamonds were small, few in number, and often took on a urine-like colour.
What has changed is we can now produce lab-grown diamonds by a process that doesn’t require the cumbersome and weighty presses of HPHT. We now use chemical vapour deposition (CVD), a variant on microwave technology. Unlike the original HPHT diamonds, CVD diamonds are grown with very good clarity and are treated to have fine colour.
Natural diamond necklace, circa 1930.
Lab-grown allure
In addition to being clean and of fine colour, CVD diamonds are grown in large sizes and in massive quantities. Individual polished CVD gems have exceeded 30 carats, and factories in India and China produce many millions of carats of these lab-grown diamonds.
Week-by-week, due to huge production volumes and heavy competition, the price of CVD diamonds has decreased. No one really wants to keep CVDs in inventory, because the price will probably drop before the next customer comes through the door.
I have spoken to a few jewellers who had CVD diamonds on memo from their suppliers. When the supplier was told there were still some lab-grown diamonds in stock in the store, the supplier said to tear up the memo. In other words, “keep them, you don’t have to pay.”
The prices of lab-grown diamonds have conventionally been quoted on the basis of “back from Rap” (referring to the standard and well-known Rapaport Diamond Report diamond pricing publication). When 1.50 to 3.00-carat CVD diamonds reached an average of 97 per cent to 98.5 per cent “back from Rap,” CVD dealers started to quote prices by price per-carat and dropped the traditional reference to Rapaport.
Most CVD lab-grown diamonds are VVS and VS clarity, and E through G colour, so there really isn’t an enormous difference between one and the next, and prices from growers are in the hundreds of dollars per-carat.
A jeweller can finally make a reasonable margin when they sell a lab-grown diamond, none of the single-figure markup seen with the competitive pricing on natural diamonds. Keystone (100 per cent) or even more is very likely.
Natural fancy yellow diamond, 11.22 carats, sold for C$212.500.
A diamond by any other name…
What worried jewellers in 1912, was whether the new “lab-grown” rubies and sapphires would slip by unnoticed and create suspicion among consumers. Fortunately, the Science of Gemmology (what is now Gem-A in Britain) solved the problem by realizing it was quite easy to separate the natural from the synthetic using a loupe or a microscope.
One of the greatest concerns for the jewellery industry right now is the complicated identification of lab-grown diamonds. We can buy screening devices that will tell us either: (A) “Pass,” it is a natural diamond, or: (B) “Refer,” meaning it might be lab-grown or might be a rare type of natural diamond. From there, we’re stuck and have to go to a lab like GIA for confirmation.
The industry is concerned when a diamond piece comes in for repair, modification, appraisal, or re-sale. How do we know that a diamond someone else sold is natural? The testers go half-way, but half of the bridal diamond jewellery in North America is lab-grown. We will be seeing a lot of “refer” indications on our diamond testers when testing re-sold diamonds. This complicates matters.
Lab-grown blue diamond, 0.80 carat.
Vintage appeal
Natural diamond prices slumped more than 30 per cent in 2023, almost all due to the lab-grown alternative. This is disastrous for the diamond industry, but retailers are happy to make sales and consumers are getting more diamond for their money.
Antique and vintage diamonds, old mine cut, old European cut, rose cut diamonds, and antique diamond jewels continue to generate excitement in the secondary market, such as at auction. Consumers love the idea of a gem or jewel that carries with it a story or some history, even if the story is somewhat vague. Antique or vintage diamonds are little parcels of memories, and consumers are drawn to them. At one time, old cut diamonds sold at a discount compared to modern diamonds. These days, old cut diamonds can even sell for a premium, perhaps because they have a different look. Very different from the cookie-cutter look of “ideal” cut modern lab-grown diamonds.
Fancy coloured diamonds are holding their price better than colourless range diamonds. Strong prices are being realized for natural pink, blue, and yellow diamonds. There are only so many of these rare gems and interest is strong.
Lab-grown diamonds are abundant and inexpensive. With the price continuing to slide downwards, it’s very likely that lab-grown diamonds will have little to no resale value. While a loupe can identify lab-grown gems like sapphire, ruby, and emerald, the process of identifying lab-grown diamonds is more complex. A buyer, appraiser or re-seller must be aware of this.
Once we have a modestly priced and reliable “natural” vs. “lab-grown” diamond tester, the industry will rest easier. We need one on each jeweller’s counter, only then will lab-grown diamonds drop into their appropriate place as an alternative to ... "
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