Bling!

Katy Perry hit the stage for a surprise performance at a star-studded NYC event on Thursday night ... and she pretty much blew the roof off the place.

The singing sensation was all glammed up in a ruffled cream gown and bejeweled heels as she arrived to celebrate the reopening of the Tiffany and Co. flagship store in Manhattan.

Katy was followed inside the iconic Fifth Avenue building by a bevy of bold-faced names. Among them were Hailey Bieber, Blake Lively, Florence Pugh, Zoe Kravitz, Tiffany Haddish, Mark Wahlberg, Gayle King, Pharrell Williams, Gabrielle Union and her hubby Dwyane Wade.

Everyone was having a great time, chatting and mingling around ... but the real fun started once Katy changed into a sheer gray dress and took the stage for her unexpected show. We're told Katy played 4 songs, including "Firework," "Dark Horse" and "Teenage Dream."

Check out video, obtained by TMZ, showing Katy belting out "Dark Horse" while doing a sexy dance knee-deep in a dense fog from smoke machines. As you can hear, the crowd ate it all up, begging Katy for more.

After Katy was done dazzling on stage, she posed for some selfies with fans.

Floyd Mayweather didn't just have diamonds all around his neck for the Gervonta Davis vs. Ryan Garcia fight over the weekend -- he apparently had 'em on his head too ... the boxing legend's jeweler tells TMZ Sports the lid Floyd rocked to the match was so encrusted in gems, it was worth over $1 MILLION, according to the jeweler!

Shuki Diamonds told us out in L.A. this week he spent over a month making the blinged-out cap for Mayweather ... and it took him even longer than that to find the perfect "invisible diamonds" for it.

Shuki says the process to get the jewels on the "The Money Team" hat was arduous ... explaining it took painstaking work to get the cap looking just right.

According to Shuki, he had to make a mold, sandblast it all, and then shine it so it'd be perfect for Floyd's head.

"It's a big process," Shuki said.

The celeb jeweler gave it to Mayweather a few weeks ago while the two were in Dubai ... and since the two are so tight, he let it go free of charge.

And, when Floyd finally broke it out in public for Tank's massive win over Garcia in the boxing match of the year -- Shuki said he appreciated it very much.

Now, Shuki estimates it could sell for over $5 million if it ever hit an auction block.

"There's only one in the world," the jeweler said. "It's become historical -- it's Floyd Mayweather."

Gervonta "Tank" Davis is winning in life ... the 29-0 fighter was gifted a $250K "Gumbo" chain minutes after knocking out Ryan Garcia, all to commemorate a new strain of weed named after the boxing superstar.

TMZ Sports has learned Davis recently signed a deal with cannabis company Gumbo Brands, who are releasing a strain called "Ape S***."

In the video, you see Tank smiling ear-to-ear as owners Alexis Majors and Karim "Luca" Butler put the expensive piece of bling -- a pendant and diamond tennis chain from Pristine Jewelers -- around his neck.

We're told former NBA star Stephen Jackson, who met with the champ in the locker room after the fight, helped facilitate the partnership between Davis and Gumbo.

Of course, Davis was already a hot commodity heading into the fight ... and even more so now that he's ended Garcia's undefeated streak, eliminating any doubt he's the king in their division.

As we reported ... Tank opted to keep things relatively low-key following arguably the biggest win of his career, celebrating the victory with some friends at Ghostbar in Vegas.

Sydney Sweeney is still with her fiancé Jonathan Davino and is NOT dating Glen Powell, multiple sources with knowledge tell TMZ ... this coming on the heels of a swarm of rumors pinning them together.

Sources with direct knowledge tell TMZ ... Sydney is still living with Jonathan and all is well between them -- they are still engaged. We're told Glen and Sydney are not dating.

Glen and Sydney have been filming for months ... the flirting, we're told, is tied to the rom-com.

Sydney was spotted with a massive diamond ring last year from Jonathan, and the 2 started dating back in 2018.

She mentioned in a February interview with Cosmo she doesn't like dating people in the entertainment industry ... makes sense, he's in the restaurant biz.

A clip of Glen and Sydney goofing around on a couch went viral, showing him dipping her while they both were full of laughs -- folks online took it as a major red flag.

The costars were then seen at CinemaCon to promote their new flick, getting just as close while posing for pics -- looking adoringly at each other.  We're told there's less here than meets the eye.

As for Glen, he's been dating Gigi Paris but she did something that raised eyebrows Monday ... she unfollowed Sydney. We have not been able to confirm whether they're still together.

Rick Ross is rocking a few shiny tokens of appreciation for recently headlining the High Tolerance 4/20 Carnival in NYC -- no biggie, just a ring, chain and pendant worth more than $100k!!!

TMZ Hip Hop obtained video of High Tolerance CEO Manny bestowing the "Rich Forever" rapper with his icy new pieces of hardware, crafted exclusively by Mazza New York.

We're told the chain retails at $40k with more than 19 diamond carats ... and the pendant consists of 14k rose gold and costs over $30k.

The ring stands as Rozay's most detailed HT piece ... it boasts more than 22 carats of VS1 and f-colored diamonds and 14k gold with a retail of over $60k!!!

High Tolerance and Rozay are in business cahoots together and plan on blessing the world with his own brand of THC this summer.

TMZ Hip Hop broke the story, Rozay signed on board in March to flood the market with their "High Collins" cannabis strain, named after his old hood in Miami.

50 Cent and his longtime girlfriend Cuban Link sparked engagement rumors over the weekend after she was spotted wearing a HUGE diamond rock while watching him perform ... but fans shouldn't start cooking up about wedding day scenarios just yet.

A rep for 50 Cent tells TMZ Hip Hop ... the ring is not an engagement ring, but the couple IS very much together.

Cuban certainly helped stir the rumor pot with her IG post showing herself backstage watching her man with a Summer Walker love ballad playing -- plus, her caption had white heart and padlock emojis.

She had to know what fans would think, but again ... we're told there's no engagement.

Trick Daddy has officially ended an era -- his gold grills, which were in dire need of an upgrade after 30 years -- are now gone!!!

Danielle Noguera, CEO of 5 Star Smiles, tells TMZ Hip Hop the Miami rap legend had a moment of clarity about his oral health after refusing to visit the dentist for 15 years. 😳

Trick’s golden chompers were first set in 1994 and remained front and center, if you will, while he made plenty of platinum raps.

But, the permanent caps decayed Trick’s teeth so badly he had to undergo bone loss surgery and currently has temporary fillings in place as his gums heal. He'll have the bottom teeth removed next week.

We’re told Trick has spent $60k on treatment thus far, and the final treatment will be done in about two months ... with a mouthful of porcelain veneers being the final result!!!

“Love & Hip Hop: Miami” will document the entire procedure and the final results in the new season’s first episode later this year.

It's out with the old and in with the new for NFL star D.J. Moore ... and we're not just talking his next team -- he upgraded his jewelry, too!!

TMZ Sports has learned ... the former Carolina receiver -- who just got shipped to Chicago as part of the Panthers' acquisition of the first overall pick in the 2023 Draft -- decided to give a shiny shout-out to his new squad ... by getting some bling that matches the Bears' colors.

We're told Moore hit up Al The Jeweler from Labelle Jewelry in Totowa, NJ for the job ... and he came up with some seriously high-quality pieces that have him pretty stoked!!

Moore is now the new owner of a chain decked out in orange sapphires and VS white diamonds ... and a matching Cartier watch!!

Of course, Al has done work for a ton of NFL guys in the past -- including Stefon Diggs, Sauce Gardner and more.

The celebrity jeweler who's suing Antonio Brown over $1 million worth of diamonds that he says the NFL star took from him tells TMZ Sports everything would be forgiven if AB would just send the stuff back.

Shuki International opened up to us on Thursday out in Los Angeles about the lawsuit he filed against the former Tampa Bay Buccaneers wide receiver this week ... and he explained he has absolutely no bad blood with the 34-year-old at all.

In fact, he told us he still loves the guy, considers him a great friend ... and plans on hitting a rap stage with him soon.

But, Shuki says AB has really put him in a bind over some of the diamonds he lent him back in 2022 ... and now, he wants Brown to either pay him for them or return 'em.

"This is just a wakeup call," Shuki said of the lawsuit against Brown. "Call me. Bring back the baby."

According to Shuki's lawsuit, the jeweler gave several items to Brown last year -- including two diamond fingers that he said were worth $500K apiece.

Shuki told us on Thursday that when he handed them over to Brown ... he expected the former football player to wear them for a little bit before giving them back so Shuki could ultimately sell them.

The jeweler, though, said when he recently tried to get Brown to return them ... the dude straight-up ghosted him.

Now, Shuki -- who's designed pieces for many high-profile clients, including Floyd Mayweather -- is pleading with Brown to get in contact with him so they can resolve everything.

"He's just got to rotate the jewelry," Shuki said. "You cannot just hold it, you know what I mean? It's mine. I gotta look good."

If you thought the styles from the 2000s were dunzo, you were wrong -- 'cause Kristin Cavallari is bringing 'em back with a splash ... alongside her "Laguna Beach" crew.

The businesswoman is launching a special jewelry line through her Uncommon James brand -- and while it's new -- it's also kinda old in a sense ... or rather, nostalgic. She and her team are calling it the Back to Laguna Collection, and it's chock full of pieces from the aughts.

Here's the best part ... Kristin actually got together with former 'LB' co-stars to shoot a promo for this retro campaign, which features all your fave personalities from the show. Yes, that includes  ... Talan Torriero, Jason Wahler, Alex Murrel, Jessica Smith and Alex Hooser.

Not just that -- but KC's ex-boyfriend, Stephen Colletti, is also in this thing. How about that?!

Indeed ... it's a welcome stroll down memory lane -- and you can see it on the 'LB' stars' faces here. FWIW, we're told they had a helluva time filming this as well ... they reunited in December at Pacific Palisades High School, where the good times (and cameras) were rolling.

Sources tell us that in between takes and during breaks, Kristin and co. were yakking it up like the old days -- as many of them hadn't seen each other in years. Pretty darn neat.

Now, as for what's included in this new Back to Laguna collection ... well, it's good stuff. A lot of these jewelry items are things you might've seen -- or even worn -- back in 2004 ... like the iconic black cord choker, gold rings (for all your fingers), earrings, bracelets and necklaces that reflect the aesthetic from back in those days.

In other words ... all the accessories you used to love as a teen and/or early twentysomething are back and for sale -- all courtesy of Kristin and Uncommon James -- plus a little help from her old friends.

It doesn't get more Orange County than this, folks.

Millie Bobby Brown and her boyfriend Jake Bongiovi are officially taking things to the next level ... the young couple's announcing their engagement.

The "Stranger Things" star shared her big news Tuesday morning by posting a pic of Jake -- the 20-year-old son of Jon Bon Jovi -- hugging her. It looks like the shot was taken moments after he popped the question, because his now fiancée is rocking a stunning diamond ring on her left ring finger.

19-year-old Millie's caption for the engagement post included a quote from Taylor Swift's song "Lovers" -- "I've loved you 3 summers now, honey, I want 'em all".

Jake and Millie have been together since 2021 when they initially met on IG. They became friends IRL, and have been inseparable since.

JB, who happens to be the spitting image of his pops, also made sure to share the special moment with his followers -- the caption on his 2 photos simply read, "Forever 🤍".

It's unclear when exactly the engagement went down ... there had been recent speculation because Millie was seen potentially wearing the diamond ring in another photo, not too long ago.

Well, turns out that rumor is true. Congrats!

Fun fact: Neither Millie nor Jake used to work on the docks (IYKYK).

We covered it all in the latest episode of The TMZ Podcast, available on all podcast platforms!

A celeb jeweler who's become famous for providing diamond pieces to high-profile athletes like Floyd Mayweather is suing Antonio Brown ... claiming the ex-NFL star owes him over $1 million.

Shuki International spelled out the allegations against the former Tampa Bay Buccaneers wide receiver in a new lawsuit filed in Los Angeles this week ... claiming he gave Brown several pieces of jewelry back in 2022, under the promise that AB would pay him $1,095,000 for it all.

The problem ... according to the suit, obtained by TMZ Sports, Brown never paid up.

Among the items that Shuki said he gave Brown included Shuki's famous "Shuki International" diamond fingers -- which the jeweler said cost $500K apiece.

Shuki also said he hooked Brown up with a rose gold black diamond version of the finger piece, a white gold chain, and a ring.

According to the suit, Brown got at least some of the items on Feb. 24, 2022 ... and agreed to pay the nearly $1.1 million price tag for it all by Dec. 1, 2022.

Shuki's attorney, Steven H. Stone, tells us the jeweler is expected to address the claims publicly later this week.

What's interesting ... we actually got Shuki out in L.A. days after he said he gave one of the fingers to Brown in March '22 -- and he seemed pleased with how AB was handling it all. What's even more interesting, Brown -- who's become a rapper following his NFL days -- has a song titled "Shuki Diamonds" ... a track he put out last year to pay homage to the celeb jeweler.

In fact, the two have actually hit the stage in the past year to perform the song together.

A national championship trophy isn't the only shiny, new thing in Angel Reese's life -- the LSU basketball star just copped some new bling -- with over 20 carats of high-quality diamonds!!!

TMZ Sports has learned ... the Tigers hooper linked up with celeb jeweler Boo Daddy Diamonds fresh off her NCAA title win over the Iowa Hawkeyes this week.

We're told Bayou Barbie is now the proud owner of several dope pieces ... including an amazing diamond tennis bracelet that's filled with VVS diamonds and 14k white gold.

She also copped two diamond chokers -- one having the initial of her first name -- and we're told the collection totaled out to 20 carats of top-quality bling!

The 6'3" forward deserves to treat herself after the year she just had -- she finished the season with 23 points and 15.4 rebounds per game ... and earned a spot on the First Team All-SEC and SEC's All-Defensive Team.

Reese -- who fractured her foot at Maryland before transferring in 2022 -- also made LSU history with the most consecutive double-doubles ... and leading the women's hoop team to their first NCAA title.

Fivio Foreign's reentry into the world of live performances is going rather smoothly ... although on a much smaller scale than the festival set he recently missed.

The Brooklyn rapper rocked the mic for Benny Da Jeweler's birthday Thursday inside the Da Mikele Illagio in Queens, NY ... his first time back onstage since his Rolling Loud health scare cancelation.

Fivio performed his hits "Say My Name" and "City of Gods" and also clowned around at the party with the kids, a great sign ... given everything he told us the last time we spoke to him.

He blamed a body shutdown on missing the festival circuit but credited nothing but plain ol' water for snapping him back into shape.

Benny's beloved by many rappers ... having hooked up Diddy, Ice Spice and Lil Tjay with bling within the past year.

Ice Spice is not the victim of a chain-snatching, but rather the target of a big ol' attempt at clout-chasing for Internet fame!!!

Video of a man claiming to have possession of Ice's icy "Queen" necklace made its rounds across social media Wednesday -- and while many fans reacted with concern for Ice, the whole drama was merely a TikTok user looking to make a viral breakthrough.

The TikTok user fended off a wave of backlash ... we mean, he was bragging about robbing a woman for her chain 😐 ... and a source close to the "Munch" rapper doubled down against the shenanigans, assuring TMZ Hip Hop that Ice has never even owed such a piece.

"Queen" branding actually belongs to Nicki Minaj ... and a closer dive through Ice's jewelry box reveals the Bronx-bred rapper rocked her custom "Isis" name pendant the past couple of years as her star power grew.

In January, she dropped her "Like..?" EP and upgraded to her current $100k chain and showed it off when she pulled up on Kim Kardashian and North West ... for an authentic viral TikTok moment.

Terence Crawford's Nebraska home was allegedly burglarized, TMZ Sports has learned ... and hundreds of thousands of dollars worth of jewelry stolen, including two luxury watches worth over 100 grand apiece.

The alleged theft occurred at the undefeated boxer's home in Omaha between March 17 and March 20, according to a Douglas County Sheriff's Office incident report.

Per the report, the unknown suspect(s) broke into his home and stole several pieces of jewelry. The haul included two gold chains featuring the logo "TBC" -- Crawford's initials -- a "Bud" personalized gold chain, and a gold cross necklace.

Two incredibly expensive watches were also reported stolen -- a diamond Patek Philippe watch and an Audemars Piguet and bracelet set.

All told, the pieces totaled over $317K ... and Crawford is asking for the public's help, even offering a hefty reward.

“I got 100k for whoever know who broke in my house and stole my jewelry," the 35-year-old announced.

This isn't the first time Crawford's home has been robbed. According to DCSO, an unknown suspect took a gold Rolex, worth a little over $137K, from the same residence in Oct. 2021.

Crawford -- 39-0 and one of the best pound-for-pound boxers in the world -- has been ordered to defend his WBO welterweight title against Alexis Rocha ... though boxing fans badly want him to fight fellow future Hall of Fame fighter Errol Spence in a super fight this year.