Library.

“Diamonds are formed from compressed coal.”

This is a widely debunked myth. Natural diamonds form deep in Earth's mantle (150–200 km down) from carbon under extreme heat and pressure—not from coal. Most diamonds are billions of years older than land plants, which are coal's source material. Coal is a near-surface crustal rock not found at mantle depths. While a speculative, marginal possibility exists that subducted organic material could contribute to a tiny fraction of diamonds, this does not validate the claim as commonly understood. The scientific consensus is clear: diamonds do not come from compressed coal.

“Diamonds are among the rarest gemstones on Earth.”

Diamonds are not among the rarest gemstones on Earth. While diamond formation requires specific geological conditions, diamonds are actually among the most common gemstones by volume — the International Gem Society calls them "likely the most common gem in nature." Numerous gemstones, including Red Beryl (1,000+ times rarer), Painite, Tanzanite, and Alexandrite, dramatically exceed diamonds in scarcity. The perception of diamond rarity was largely shaped by marketing, not geological reality.

“It is possible to create diamonds from peanut butter using scientific methods.”

It is technically possible to convert carbon from peanut butter into diamond under extreme laboratory pressure, as demonstrated by geophysicist Dan Frost at Germany's Bayerisches Geoinstitut. Diamond crystals did form before hydrogen released from the peanut butter destroyed the apparatus. However, this was a single, unreplicated demonstration — not a peer-reviewed or repeatable method. Established diamond synthesis uses pure carbon feedstocks, not complex organic mixtures. The claim is literally true but gives a misleadingly optimistic impression of feasibility.