Bible dictionaries
Hyacinth
What Bible dictionaries say about “Hyacinth”, one article after the other.
International Standard Bible Encyclopedia (ISBE 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."
International Standard Bible Encyclopedia — James Orr, general editor and contributors; CrossWire SWORD module ISBE 2.2
The article in ISBE 1915Smith’s Bible Dictionary
used in the Revised Version for jacinth in (Revelation 9:17) It is simply another English spelling of the same Greek word.
William Smith; revised by F. N. Peloubet and M. A. Peloubet; CrossWire SWORD module Smith 1.3
The article in Smith