Call it the Case of the Missing Platinum.

It began when employes of a Gaithersburg manufacturer of solar cells decided to fish scrap silver solder out of the company's trash bins to sell on their own.

"We were keeping the scrap silver solder and the scrap copper in the shop for a slush fund for weekend parties," says a former employe of Semix, a metal-processing division of Rockville's Solarex Corp.

But the stakes grew higher when the workers found out that the company was also discarding platinum. The pale silvery metal that currently sells for about $300 an ounce--and a year ago was worth about $400--is so valuable that it's known as "white gold."

And that's why the employe and several other workers no longer work at Semix--they were fired a year ago for scavenging the company's trash bins for platinum, selling it to precious-metals firms, and pocketing the proceeds. The company said the platinum was supposed to be recycled, but the former employe said it wasn't.

"I just started picking it up out of the trash can, out of the dumpsters, out of the parking lots outside," says the ex-employe, who made about $300 selling the metal, and has asked not to be identified. There was no skullduggery involved, he says. "I didn't make a secret of this." When a supervisor asked him to stop selling the metal, he did, the former employe says.

His share of the lode, however, was apparently small compared to what the other employes made. In all, between $5,000 and $10,000 worth of platinum disappeared from Semix's factory, according to statements by Semix officials contained in records in Maryland District Court in Rockville. The records stem from Semix's attempt to prosecute the employes.

That attempt failed, according to the former employe, because the company couldn't show that it had a system for saving or recycling the valuable scraps. In short, it was throwing them away, the employe said. The court papers, however, say that the platinum wire was "supposed to be kept and recycled by the victim corporation."

Charges against the employes were dropped, and the fired workers got favorable letters of recommendation from Semix in exchange for a promise that they wouldn't sue the company, state or local officials for malicious prosecution, the court papers said.

"I was really upset about the whole deal, because I did not actually steal this," says the former employe, who now works at another area high-technology firm.

Semix officials don't want to talk about what happened. "We don't want any publicity," says Amedee Dean, the company's vice president for manufacturing. "It's not something we really want to talk about."

But Dean does say: "It's one of those things that happens periodically in an industrial environment."

The former employe says he understands from friends still working for the company that Semix now has a precious-metal recycling program. That, he says, is a change from the company's previous practices. "It was such a nonchalant attitude," he says.