A routine jewelry shopping spree turned into high drama for Floyd Mayweather on Thursday -- when things got heated with a store owner over a VERY expensive stone and cops were called, TMZ Sports has learned.
We're told Floyd was shopping at the Diamond Club fine jewelry shop inside the Seybold Building when Mayweather zeroed in a stone.
Our sources tell us ... a verbal altercation broke out between Mayweather and the shop owner -- and things got so intense, someone inside the shop called police.
By the time cops arrived, we're told Mayweather had already left the shop.
We reached out to Mayweather and the shop owner -- but everyone is being VERY tight-lipped about the situation.
We also contacted Miami PD -- and a rep would only confirm that cops responded to the shop regarding an issue involving a "high profile celebrity" ... but wouldn't get into specifics.
Unclear if cops are investigating or if the matter is considered closed.
Remember, Mayweather spends MILLIONS of dollars at jewelry stores all over the world -- so you'd think Floyd showing up at your shop would be like hitting the lottery.
But, that's clearly not what happened here.