peridot/ˈpɛɹ.ɪ.dɒt/EtymologyFrom Middle English peritot, from Anglo-Norman peridou, peridout, Middle French perido, peridon, of uncertain origin; later reborrowed from modern French péridot.nounA transparent olive green form of olivine, used as a gem.“Gem-quality olivine is known as peridot, which has a subtle green light all its own.”A yellow-green color, like that of the peridot.