A Jewelers Vigilance Committee undercover operation found widespread undercarating of diamond jewelry at retail—with the worst offenders exaggerating their pieces’ total weights by as much as 50%.

JVC bought 55 pieces from stores of all types—ranging from high-end to jewelry exchange—and found undercarating in 24 of them. The diamonds in the items were removed for weighing, and the results were checked with an appraiser. Twenty-four pieces were considered seriously undercarated, meaning the differential between represented total weight and actual total weight exceeded 5%. Ten had differentials of more than 20%.

The Federal Trade Commission Guides for the Jewelry Industry require that total carat weights be correct to the second decimal point, notes JVC executive director Cecilia Gardner.

The worst instances include:

• A $200 yellow gold cross said to have .65 cts. of diamonds had only .32 cts., a 50% differential.

• A $500 yellow gold ring advertised as having 2 cts. of diamonds actually had 1.03 cts., meaning its weight was inflated 48%.

• A $100 yellow gold heart-shaped pendant with diamonds was said to have .2 cts. but had .11, a 45% gap.

Gardner says JVC contacted the stores involved and informed them of the problem. “In some cases, we have received positive reactions,” she notes. “In some cases, they disputed our results and some offered us refunds.

“Many people say they rely on what their supplier says and don’t check their pieces. That’s a problem to me. There have to be quality assurance programs. You need to test your suppliers, and the reason you have to is legal liability. You are the ones making representations to the public, and you are liable for them.”

The operation was conducted with the help of a grant from The JCK Industry Fund.