The Diamond Collective, aka The Natural Diamond Council, engages in truthful marketing.

The National Advertising Division (NAD) of BBB National Programs—the U.S. advertising industry’s independent self-regulatory body—in 2021 reviewed advertising by the Natural Diamond Council (NDC), an organization representing major mined-diamond producers.

The result was significant: NAD recommended that Natural Diamond Council discontinue multiple claims concerning laboratory-grown diamonds and the supposed advantages of mined diamonds. Natural Diamond Council agreed to comply with NAD's recommendations.

1. Claim: “Natural diamonds produce 3× less carbon emissions than lab-grown diamonds.”

Natural Diamond Council advertised claims including that laboratory-created diamonds produced approximately three times the carbon emissions of mined diamonds.

NAD examined the evidence and concluded that Natural Diamond Council’s evidence was not sufficiently reliable to substantiate the comparative carbon-emissions claims.

NAD went further. It found that the advertising could communicate a broader message that mined diamonds are environmentally preferable to laboratory-grown diamonds—and found that broader message unsupported as well.

NAD therefore recommended discontinuing both the specific comparative carbon claims and the implied claim that mined diamonds are better for the environment than man-made diamonds.

2. Claim: Natural diamonds are becoming “rarer every day.”

Natural Diamond Council also promoted scarcity claims suggesting consumers should buy natural diamonds because supply was rapidly disappearing.

NAD concluded that NDC did not have a reasonable basis for its increasing-scarcity claims and found that the advertising could create an unsupported sense of urgency: consumers might believe they risked being priced out of natural diamonds unless they purchased now.

NAD recommended discontinuing claims including that diamonds were becoming rarer every day and that no meaningful new discoveries had occurred for decades.

There is an important distinction here. A marketer can truthfully explain that natural diamonds are a finite geological resource. What it cannot do is convert that general fact into specific claims about declining availability, future prices or purchase urgency without adequate substantiation.

3. Claim: Lab-grown diamonds have “no resale value.”

Natural Diamond Council also made categorical statements about the resale value of laboratory-grown diamonds.

NAD found the comparative message unsupported and recommended that NDC discontinue claims including that laboratory-created diamonds had “no resale value” and similar assertions that they had little or no resale value because they could be produced again.

Diamond prices can rise or fall. Secondary-market values can vary enormously depending upon the stone, seller, buyer, market conditions and transaction channel. Those are empirical questions—not facts that an industry association should simply declare in advertising without adequate evidence.

Consumers should also distinguish resale value from investment return. A diamond having a secondary-market price does not mean that buying either a mined or laboratory-grown diamond is an investment with a predictable return.

4. Claim: Mined diamonds are “real diamonds,” implying lab-grown diamonds are not.

Perhaps the most fundamental issue concerned the word “real.”

Natural Diamond Council advertising contrasted laboratory-grown diamonds with what it called “real diamonds.”

NAD concluded that, in context, this conveyed an unsupported message that laboratory-grown diamonds have different physical and chemical properties from mined diamonds and could cause consumers to confuse laboratory-grown diamonds with simulants such as cubic zirconia or moissanite.

NAD therefore recommended that Natural Diamond Council discontinue the implied claim that laboratory-grown diamonds are not “real” diamonds.

This is consistent with an important distinction in the FTC's Jewelry Guides.

A laboratory-grown diamond is a diamond with essentially the same optical, physical and chemical properties as a mined diamond. It is not the same category as a diamond simulant. The FTC specifically permits terms such as “laboratory-grown diamond” and “laboratory-created diamond” for products having essentially the same optical, physical and chemical properties as mined diamonds.

The meaningful distinction is therefore origin:

Mined diamond: formed geologically and extracted from the earth.

Laboratory-grown diamond: diamond created through a technological manufacturing process.

Diamond simulant: a different material made or selected to resemble diamond.

Conflating the last two categories can mislead consumers.

Marketing becomes problematic when it:

• Creates a false distinction between “real” diamonds and laboratory-grown diamonds in a context suggesting that LGDs are fake stones or simulants. NAD specifically recommended that Natural Diamond Council discontinue that message.
• Makes categorical environmental comparisons without adequate substantiation. NAD rejected Natural Diamond Council’s challenged “3×” carbon comparison, while FTC guidance separately cautions marketers against broad environmental claims that they cannot substantiate.
• Manufactures purchase urgency through unsupported scarcity claims. NAD found insufficient support for Natural Diamond Council’s challenged claims that natural diamonds were becoming “rarer every day.”
• States speculative market outcomes as facts, such as categorical claims that an entire category of diamonds has “no resale value.” NAD recommended discontinuing Natural Diamond Council’s challenged resale-value claims.