Expert testing backs up Zale’s claim that its Celebration Fire diamond is the “most brilliant diamond in the world,” the retailer claims in a Nov. 29 legal filing.

The Ohio federal court filing responded to a lawsuit by competitor Signet, which termed the claim “false.”

“Precision Gem Grading Laboratory tested the brilliance of numerous diamonds from national retail jewelry stores using patented light measurement technology developed by ImaGem Inc., and the results clearly demonstrated that the Celebration Fire is more brilliant,” the filing said.

It also claimed that Sterling’s expert, Randy Wagner of GemEx, also found the Celebration Fire more brilliant than other tested stones.

The company also complained that Signet’s request for an injunction and expedited discovery will hurt it during its busiest time of the year.

In its response, Signet argued that time was of the essence.

“If Zales succeeds in being able to stretch its deceptive campaign through the holiday season, it will misappropriate many consumers whom Sterling will never have the opportunity to get back,” Signet’s reply, filed Nov. 30, said.

It also argued that Zales’ response still failed to back up its claim that the Celebration Fire is the “most brilliant diamond in the world,” as Zale previously sold the Fire under the name “Brilliant 10.”

“By ‘introducing’ its secretly rebranded Brilliant 10 as a ‘revolutionary improvement’ on existing diamonds—a deceptive act in itself— Zales concedes it has been claiming, since October, that its Celebration Fire is more brilliant than the same diamond sold under a different trademark by others,” the filing said.

JCK