Herodotus on Emerald

“Polycrates considered which of his treasures it would most grieve his soul to lose, and came to this conclusion: he wore a seal set in gold, an emerald, crafted by Theodorus son of Telecles of Samos.”

“I took ship for Tyre in Phoenicia, where I had learned by inquiry that there was a holy temple of Heracles. There I saw it, richly equipped with many other offerings, besides two pillars, one of refined gold, one of emerald: a great pillar that shone at night.”