Natural diamonds retain their value, have better resale value than lab diamonds.

The diamond mining cartel controls pricing for mined natural diamonds whereas lab diamond prices are competitively priced in a competitive producer market. The lack of cartel pricing control is the sole reason why lab diamonds cost less.

The claim of retention of value is wrong in two profound ways:

• Retail vs wholesale prices. The statement suggests that it is a good investment to buy a mined natural diamond but retail prices alone are a factor above wholesale (repurchase) prices, so consumers will lose 80% of what they spent just based on the difference between retail and wholesale pricing. It is disingenuous for any jeweler or marketer to suggest that buying diamonds at retail pricing is an investment and of good value.
• Wholesale prices for natural diamonds have been in free fall. The wholesale market pricing for natural diamonds has dropped to half.

According to data from Rapaport Group, the diamond trading platform, a standard one-carat stone averaged $8,007 in September 2021. By September 2026, that figure had fallen to approximately $3,898; a decline of 51% in just five years. The Diamond Standard Index, which tracks investment-grade diamonds, hit its lowest level on record in early August 2026, hovering just above 2,500.

Misleading Marketing by Diamond Miners

NAD found the Natural Diamond Council’s challenged claims about mined diamonds’ scarcity and relative resale value unsupported.

The National Advertising Division (NAD), the U.S. advertising industry’s independent self-regulatory body, asked the Natural Diamond Council, which has now renamed itself to “The Diamond Collective”, to stop making certain claims regarding mined diamonds’ scarcity and resale value.

NAD recommended that the Natural Diamond Council discontinue certain claims about the resale value of lab-grown gems; among the claims that the NAD frowned upon:

• “Laboratory created diamonds are currently sold at a slightly reduced price compared to natural diamonds, but the cost continues to decline due to mass production.… Therefore, they have little to no resale value.”
• “A laboratory created diamond has no resale value and its price is falling rapidly.”
• “[M]ass-produced lab-grown diamonds are sold at comparable prices, but have little to no resale value because they can be endlessly replicated.”

The NAD wrote that the submitted evidence “does not provide a reasonable basis for claims about man-made diamond’s and natural diamond’s respective resale values, especially claims that man-made diamonds have ‘little or no resale value.’”