A  third-generation gem trader in Ratnapura, Sri Lanka was digging in his backyard when he stumbled upon a massive sapphire cluster that is said to be worth roughly $100 million.

According to The New York Postthe owner of the stone was given a tip that there might be some rare gems on his property. When he began digging, he found the $2.5-million carat. Only wanting to be identified by his last name, Gamage, the owner explained how he found it.

“The person who was digging the well alerted us about some rare stones. Later we stumbled upon this huge specimen.”

This all happened a year ago because after Gamage alerted authorities of his find, it took them that long to clean and certify it. The cluster weighs roughly 1,124 pounds and was dubbed the “Serendipity Sapphire.”

“I have never seen such a large specimen before,” Dr. Gamini Zoysa, a renowned gemologist, told the BBC. “This was probably formed around 400 million years ago.”

The city where the sapphire was found is known to be the gem capital of the world, and Sri Lanka made half a billion dollars last year on gem exports alone. The chairman of the National Gem and Jewelry Authority, Thilak Weerasinghe, added that he believed this cluster to be the biggest in the world.

“It is a special star sapphire specimen, probably the biggest in the world,” he said. “Given the size and its value, we think it will interest private collectors or museums.”