windows - rather, “battlements”; literally, “suns”; applied to battlements from their radiated appearance.
agates - rather, “rubies.”
carbuncles - literally, “sparkling gems”; the carbuncle when held to the sun becomes like a burning coal.
all thy borders - rather, “thy whole circuit,” consisting of precious stones. The glory of the Church on earth, when the Hebrew Church, according to the original design, shall be the metropolis of Christendom.