hyacinth: [16] Greek huákinthos denoted a plant with deep red flowers which according to legend sprang from the blood of Hyacinthus, a beautiful youth whom Apollo loved but accidentally killed. It probably came from some pre-Hellenic Mediterranean language, and was remodelled in Greek on the basis of Hyacinthus’s name. It is not clear what sort of plant the original hyacinth was, but by the time the word reached English (via Latin hyacinthus and French hyacinthe) it had been adopted for the bluebell and its immediate relatives.
Greek huákinthos was also used for a variety of precious stone, probably originally the sapphire. This meaning too followed the word into English, but is now little used, having been taken over by jacinth [13] – itself a descendant of Latin hyacinthus. => jacinth[hyacinth etymology, hyacinth origin, 英语词源]