For the past 20 years, Jesse Lofgren has slowly amassed a collection of Lake Superior agates.

But when he returned from a monthlong business trip earlier this week, Lofgren discovered that $60,000 worth of the gemstones were missing from his home.

Lofgren said a burglar smashed into two of his display cases, each about the size of a refrigerator, and stole 75 of his agates.

Lofgren, who described himself as a "very private person" said only a few people have seen the collection in his home.

The Monticello man has since shared his story on television and social media. He said he's also asked other agate collectors to keep an eye out for his collection.

"It makes it very difficult for the collection to get sold," he said.

An agate photo from Jesse Lofgren

Lofgren, who owns a window-cleaning business, said he doesn't have homeowners insurance.

"I probably could have recovered my losses," he said.

The Wright County Sheriff's Office is investigating the incident, and Lofgren said he's considering hiring a private investigator. He is offering a $5,000 reward for the collection.

Lofgren has also created a GoFundMe page to help recoup his loss.

Haley Hansen is a University of Minnesota student on assignment for the Star Tribune.