used in the Revised Version for jacinth in (Revelation 9:17) It is simply another English spelling of the same Greek word.
International Standard Bible Encyclopedia 1915
hi'-a-sinth (huakinthos): the Revised Version (British and American) uses this word in Re 9:17 for the King James Version "jacinth," with reference, not to stone, but to dark-purple color. In Re 21:20, where stone is meant, the Revised Version (British and American) translations "sapphire."