Fact: the most popular gemstone is a diamond. But do you know these other fascinating facts about our favorite gem?

1. Romans and Greeks believed diamonds were tears cried by the gods.

Greek philosopher Plato suggested diamonds were living spirits that took on the body of stones. Many Romans and Greeks also believed diamonds were either crystallized tears cried by gods or broken splinters from fallen stars.

2. Largest diamond ever was the Cullian diamond weighed 1.33 pounds

History.com says the Cullian is the largest diamond ever found — weiging 1.33 pounds. In 1905, Frederick Wells was mining in South Africa when he noticed something sparkling in the corner of his eye. He took the diamond and presented it to Sir Thomas Cullinan (the owner of the mine).

Eventually the diamond made its way to King Edward VII as a birthday gift. Edward had the diamond cut by the owner of Asscher Diamond Company, Joseph Asscher. After he studied the diamond for nine months, Asscher cut the ring and then fainted from nervous exhaustion. Can you blame him?

3. The first engagement ring proposal was in 1477.

The first recorded ring proposal was from Archduke Maximilian of Austria to Mary of Burgundy in 1477. Her ring was set with diamonds in the shape of an “M.” It would be hard to turn down a ring like that — but would you want the last name “Maximilian”?

4. Scientists can make diamonds from peanut butter

Dan Frost, a scientist in Germany, discovered how to make diamonds from peanut butter and carbon dioxide. According to the BBC, Frost put peanut butter (a material that is rich in carbon) under high pressure and added hydrogen. Eventually, diamonds emerged. Although very cool, you probably can’t do this with your jar of Jif at home.

5. $83.2 million — highest price paid for a diamond.

Back in 2013, the “Pink Star” sold for $83 million in Switzerland. However, the buyers never gave their names. The same diamond was sold again for $71.2 million in March because the unknown buyer couldn’t afford the payments, according to Forbes. Are there many people who could afford it?