Of uncertain derivation; the hyacinth or {jacinth} that {is} some gem of a deep blue {color} probably the zirkon: - jacinth.
Verse
Matrix
Rev 9:17And thus I saw the horses in the vision, and them that sat on them, having breastplates of fire, and of jacinthG5191, 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.