Nov 22 2013Save11/22/13Goodman's Paradox introduces us to the color "grue"Esther Inglis-Arkell138SaveEver heard of the color grue? According to some, you see it whenever you stare at an emerald. Think about it as…
Aug 29 2012Save8/29/12Acid and Gold: The Modern Alchemy of Artificial GemstonesEsther Inglis-Arkell18SaveEveryone knows that humans can make artificial diamonds. But did you know that we can make sapphires, emeralds, and…