And this is how I saw the horses and their riders in my vision: the riders had breastplates [the color] of fire and of hyacinth (sapphire blue) and of brimstone (yellow); and the heads of the horses looked like the heads of lions; and from out of their mouths came fire and smoke and brimstone (burning sulfur).

And the foundations of the wall of the city were garnished with all manner of precious stones. The first foundation was jasper; the second, sapphire; the third, a chalcedony; the fourth, an emerald;