An agate stone could sell for £7,300 (AU$12,900) thanks to its uncanny resemblance to Sesame Street’s Cookie Monster.
The rock was discovered in the Rio Grande dol Sul region near Soledade in Brazil, and while it looks like an egg-shaped stone from the exterior, once it’s split in half the resemblance to the Cookie Monster is startling.
Geologist Mike Bowers posted a video of the rock on his Facebook page where it was shared thousands of times.
And while agate itself isn’t that valuable, the unusual “face” within means it could be worth thousands, Bowers told Mail Online.
“I think this is probably the most perfect Cookie Monster out there. I have seen others but here you have it complete (both sides),” he said.
“Prices can be very high. I was proposed over $10,000 by 5 different buyers. Rare.”
Agate is normally formed within volcanic or metamorphic rocks and has been used in jewellery as far back as Ancient Greece.