Jacinth – A precious blue or red gem.
This word appears 2 times in Scripture: Both instances are found in Revelation.
It is claimed that originally this word was probably referring to a sapphire. But, because Scripture distinctly uses both words, we know that the scholars are wrong.
The word-search for jacinth renders an entirely different word, Zircon, which is “Any of the reddish-orange or brownish varieties of zircon or certain other minerals, used as a semiprecious stone”.
See also Brimstone