The “Cookie Monster” Agate discovered in Brazil is worth around $10,000. - (Left) A rare piece of volcanic agate rock (deep blue quartz crystal) which has a striking resemblance of Sesame Street’s Cookie Monster. (Right) Close up view of the rock (Photos by Mike Bowers, screenshots of his video)
A rare piece of volcanic agate rock was discovered in the Rio Grande do Sul region near Soledade in Brazil last November 2020. It is an oval-shaped rock with a hard, white pitted outer shell. On the outside, it looks like a perfect egg. When you split the rock at the center, you will see in each of the two halves a strange resemblance of Cookie Monster, a character from the famous children’s television show “Sesame Street”.
At first look, the rock’s photos and video which went viral on the internet seems surreal, but it is actually a unique piece of rock that was naturally formed in a volcanic environment, according to its owner. The rock is a deep blue quartz crystal and was discovered and found by Lucas Fassari, a gemologist and explorer in Brazil.  It was sent to Mike Bowers in California. Bowers is an American geologist and specializes in these types of rocks. He said that it could be worth as much as $10,000 due to its rare features. 
Bowers uploaded on his personal social media account a video of the rock with the caption “Cookie Monster agate from Brazil” with a background music of Cookie Monster singing about the letter “C”. His post immediately became viral online. The actual cost of the rock when bought from Fassari was not revealed by the current seller. 
“I think this is probably the most perfect Cookie Monster out there. I have seen others but here you have it complete on both sides. This is very unusual. There are a few famous agates out there: the owl, the scared face. There are many approximate ones but it is rare to find one so well defined like this,” Bowers said. “Prices can be very high. I was proposed over $10,000 by five different buyers. Rare.”
While his viral video of the Cookie Monster agate is fascinating, it also brought some doubt to most people. Is it really possible for nature to produce a semiprecious stone with such strange appearance? What are agates and how are they formed in the first place?
Geology.com described the agate as a translucent variety of microcrystalline quartz. It is formed by the deposition of silica from groundwater in the cavities of igneous rocks. Agates are formed by the deposits of silica from groundwater in the cavities of igneous rocks. The agate deposits in concentric layers around the walls of the cavity or in the horizontal layers building up from the bottom of the cavity. As a result, layered patters are then formed. In some agate formations, these cavities are lined with crystals, therefore called geodes. A geode is a round rock with a hollow space lined with crystals, just like the Cookie Monster agate.
Agates come in a wide range of colours such as brown, red, yellow, gray, black, pink and white. The colours are produced by the impurities during its formation and they are formed in alternating layers within the agate. Now, the variations in colours are produced once groundwater of different compositions leak into the cavity. The banding within a cavity is a manifestation of change in water chemistry. As an end result, agates end up having interesting colours and patterns.
Based on this general description of agate, the authenticity of the Cookie Monster agate seems legitimate. Bowers reported to Daily Mail UK that the rock is indeed real.  A fact-checking website, Snopes.com. also claimed that rock is authentic.  TechnologyTimes.pk on the other hand stated, “As of the moment, there are no news yet as to whether Bowers actually intends to sell the rock or not, and about its current value as of the moment. Furthermore, no authorities have confirmed whether the rock is real or fake. If it is, sure enough, its value will increase over time as more and more people take interest in the unusual rock. Who would’ve known Cookie Monster would make so much numbers in a rock?” (--Marcelle P. Villegas, PRJ)
 Boyle, Darren (19 Jan. 2021). Daily Mail UK. "What a muppet! Geologist finds incredibly rare lump of volcanic agate rock which looks exactly like Sesame Street's Cookie Monster". Retrieved from -
 Hart, Matthew (26 Jan. 2021). Nerdist. "Gemologist Cracks Open Rock, Finds Cookie Monster's Face".
 Evon, Dan (26 Jan. 2021). Snopes. "Is the 'Cookie Monster Rock' Real?".
 Noor, Mufliha (25 Jan. 2021). Technology Times.pk. "'Cookie Monster' Rock From Brazil: Real or Fake?".