Thieves have recently broken into jewelry stores in Burlington, Medford, and Everett, storeowners and authorities said.

The most recent incident happened before dawn Thursday, when an apparent jewelry thief, or thieves, attempted to bust into Gold N’ Oldies Jewelry and Antiques in Everett.

They made it in the front door at around 5 a.m., but inside they encountered an unexpected barrier: steel grates protecting the establishment’s prized jewels, owner Conrad Casarjian said in an interview Thursday. They made out with a single silver ring worth no more than $30.

“We’re probably one of the few stores that has steel grating,” Casarjian said. “I like to say, it’s great to have grates. It stopped them from entering, that’s for sure.

The thieves had apparently grabbed two more rings in the attempted robbery. They were found on the floor when store employees were cleaning up Thursday morning.

“If you have less security they can get $30,000. Here, they got about $30,” said Casarjian, who’s owned the business for 36 years.

As for the door they shattered to get in? Casarjian’s landlord works for a glass company.

“I didn’t even get here to open for the day, and the landlord had already replaced the glass,” he said. “And we’re back in business.”

Everett police declined to comment citing an ongoing investigation into the incident.

Two other jewelry stores were targeted early Sunday morning. At about 3 a.m. Sunday a group of thieves broke into A Touch of Midas Jewelers in Burlington.

David Milano, the owner of the jewelry shop, said they smashed a window and caused thousands of dollars in damage.

“This was a smash and grab,” Milano said in a telephone interview. “They smashed a bunch of our cases, got nothing and left. Well, I shouldn’t say they got nothing…They didn’t get anything that would croak us.”

Milano said his shop was open for business like usual Tuesday, but he is worried.

“What if they come back?” he asked.

Hours later on Sunday, thieves broke into Roland’s Jewelry at 70 High St. in Medford.

Tom O’Leary, the manager of Roland’s Jewelry, said that shortly before 6 a.m. Sunday a group of six to nine people broke into the shop.

“They smashed the door and reached in and turned both locks,” O’Leary said. “They smashed four cases and they took jewelry from two of the cases.”

This is not the first time that Roland’s has been targeted by thieves, but in the past it has been one person operating alone. This is the first time a group of people stole from the store, he said.

“It’s terrible,” he said. “But it seems like it’s a sign of the times. People get desperate.”

O’Leary estimated that they caused between $3,500 to $4,000 in damage to the cases and door, and stole about $12,000 in inventory.

O’Leary is thankful that it happened when the store was closed.

“It happened at night, and no one was in the store, no one got hurt,” O’Leary said. “Merchandise can replaced, and cases can be fixed.”

Emily Sweeney can be reached at emily.sweeney@globe.com. Follow her on Twitter @emilysweeney and on Instagram @emilysweeney22. Andrew Brinker was a Globe intern in 2022. Follow him on Twitter at @andrewnbrinker.

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