Persistence pays.

Kevin Kinard was visiting Arkansas' Crater of Diamonds State Park when he discovered a 9.07 carat diamond.

Kinard, from Maumelle, Arkansas, has been going to park since a second-grade field trip -- even though he had always come back empty handed.

He's 33 now. And he's got the second-largest diamond found in the park's history.

Kinard was at the park with friends on Labor Day.

"Anything that looked like a crystal, I picked it up and put it in my bag," he said in a news release from the park.

The bank branch manager then came across a marble-sized crystal.

"It kind of looked interesting and shiny, " Kinard said. "I just thought it might've been glass."

After hours of searching, the friends stopped by the park's Diamond Discovery Center to have their stones examined.

Moments later, Kinard was called into an office and given the good news.

"I honestly teared up when they told me. I was in complete shock," he said.
He decided to call his find the Kinard Friendship Diamond.

"It weighs 9.07, and I found it on 9/7. I thought that was so unique."

More than 75,000 diamonds have been unearthed at the park since the first ones were discovered in 1906.

The park has a "finders keepers" policy, which is pretty generous considering the many large diamonds that have been found there, as regular CNN readers may recall.

Among the finds: