FactsIP FactoidsSubjectsScience FactsWeird Facts Diamonds can be made from peanut butter. By IP Factly - Sep 29, 2016 0 256 Share on Facebook Tweet on Twitter Image credit: Kim Alaniz/CC BY-ND 2.0 Image credit: Kim Alaniz/CC BY-ND 2.0 But only under very high pressure and temperature so not everyone can do it. Also, the resulting diamond isn’t shiny. It looks muddy because of the impurities in peanut butter and is small, about the size of a fennel seed.