All that glitters is not gold, especially when it comes to Donald Trump.

Charlie Sheen says the presumptive GOP nominee once gave him an impromptu wedding gift of what he said were platinum and diamond cufflinks.

But there was one problem. They weren't actually the real deal. And when the Hollywood actor had them valued, he claims they turned out to be fake.

Sheen recounted the incident on "The Graham Norton Show," which aired in the United Kingdom on Friday night.

"I'm really not a fan," Sheen said of Trump, who spoke to him at a dinner around five years ago. "He says 'these are platinum diamond Harry Winston' and he pulls off his cufflinks and he gives them to me."

Six months later, Sheen asked a jeweler appraising jewelry at his home to take a look at the ’links.

"She took the loupe, spent about four seconds, and kind of recoiled from it — much like people do from Trump — and says 'in their finest moment, this is cheap pewter and bad zirconias,'" said Sheen, who dismissed the real estate mogul as a "charlatan."

"And they’re stamped 'Trump.' And I just thought, 'what does this really say about the man, that he said, 'here's a great wedding gift,' and it's just a bag of dog shit?" Trump has so far not commented on the claims.

Sheen revealed he’d been diagnosed as HIV positive in November. He told Norton the diagnosis had been “liberating” and that he’d been taking part in drug trials to combat the condition ever since. “It was an opportunity to stop the self-loathing and the ‘why me’ and be part of something genuinely important,” he added.

Watch the full clip above.

Editor’s note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims — 1.6 billion members of an entire religion — from entering the U.S.