2 verses
And thus I saw the horses in the vision, and them that sat on them, having breastplates of fire, and of jacinth, and brimstone: and the heads of the horses were as the heads of lions; and out of their mouths issued fire and smoke and brimstone.
The fifth, sardonyx; the sixth, sardius; the seventh, chrysolite; the eighth, beryl; the ninth, a topaz; the tenth, a chrysoprasus; the eleventh, a jacinth; the twelfth, an amethyst.
Matthew George Easton, 1897
Properly a flower of a reddish blue or deep purple (hyacinth), and hence a precious stone of that colour (Rev. 21:20). It has been supposed to designate the same stone as the ligure (Heb. leshem) mentioned in Ex. 28:19 as the first stone of the third row in the high priest’s breast-plate. In Rev. 9:17 the word is simply descriptive of colour.
William Smith, 1884
a precious stone, forming one of the foundations of the walls of the new Jerusalem. (Revelation 21:20) Called hyacinth in the Revised Version. This is simply a different English rendering of the same Greek original. It is probably identical with the lighure of (Exodus 28:19) The Jacinth or hyacinth is a red variety of zircon, which is found in square prisms of a white, gray, red, reddish-brown, yellow or pale-green color. The expression in (Revelation 9:17) "of jacinth," is descriptive simply of a dark-purple color.