Gemstones
A gemstone is any of a number of mineral forms, typically crystalline, that are greatly valued in some cultures. Among the most valuable are diamonds (crystalline carbon), rubies and sapphires (gem grade corundum), and emeralds (beryls). By the 23rd century, it was possible to synthesize these in any quantity required, rendering them essentially valueless. In 2267, Korob attempted to bribe members of the USS Enterprise crew with such stones; his flawed research led him to believe that they would be swayed by such a fortune. (TOS: "Catspaw")