Revelation 9:17

ὑακινθίνους; Primas[339] and Tyc[340] read spineas= ἀκανθίνους.

[339] Primasius, edited by Haussleiter.
[340] Tyconius.

17. ἔχοντας θώρακας. This must be understood of the riders chiefly, but perhaps not exclusively: comparing Revelation 9:9 we cannot be sure that St John would not use the word “breastplate” of the defensive armour of a horse, if he had such in his mind. In fact, the word is used in later Greek of defensive armour generally, not the breastplate only.

πυρίνους καὶ ὑακινθίνους καὶ θειώδεις. As the last adjective only means “like brimstone,” it is possible that the two former indicate colour rather than material, which is strictly implied in the terminations, the rather that fire and “jacinth” is a somewhat incongruous combination. Jacinth is the modern transliteration of ὑάκινθος, the classical transliteration of the oriental jacuth, the name of a class of stones to which the sapphire belongs, and this was the common ancient meaning of the word; but it was also applied to stones of the same kind and of different colours, red or orange. In the middle ages it became common to speak of red and blue “jacinths” as rubei or sapphirei, and then the epithets superseded the noun. Most “jacinths” were known as rubies or sapphires, and the original name was left for any stone of the least common and precious colour of the original “jacinth.” Here the horsemen had breastplates of fiery red, of smoky blue, and of sulphurous yellow. Whether all had tricoloured armour, or whether there were three divisions, each in a distinctive uniform, may be doubted: but the three plagues corresponding to these colours, which we hear of directly after, are almost certainly inflicted by the whole army alike: and this affords some presumption that the attire of each was symbolical of all three.