Zale and Sterling have long battled each other in America’s malls. Now they are also fighting in a court of law.

On Nov. 13, Sterling Jewelers filed a lawsuit against Zale Corp. in Northern District of Ohio federal court, charging that Zale is engaged in false advertising by calling its Celebration Fire diamond “the most brilliant diamond in the world.”

It notes that Zale’s advertising says the claim is based on “independent laboratory testing conducted in 2012 of round-cut diamonds from select leading national jewelry store chains.” The lab is not specified.

But Sterling’s court papers argue that brilliance is “not a statement of subjective opinion but is capable of being systematically, reliably, and scientifically measured.”

They maintain that by comparing to Celebration Fire only to diamonds at other “national jewelry store chains,” Zale is giving an incomplete picture.

“Zales’ claim that it has proven its Fire diamond to be more brilliant that any other cut of diamond in the world can be true only if its Fire diamonds have been tested against every other cut of diamond in the world,” Sterling says.

It also adds that “even as to the limited sub-set of diamonds tested in the test referenced by Zales, those tests do not constitute competent and reliable scientific evidence that Zales’ Fire diamond is the most brilliant diamond in the world.”

The suit charges Zale with false advertising under the Lanham Act, and deceptive trade practices under the Ohio Deceptive Trade Practices Act.

At press time, Zale had not filed a response. However, spokeswoman Roxane Barry tells JCK: “Our advertising was based upon testing by an independent laboratory and our ads make that fact clear. We believe the lawsuit is without merit.”

JCK