Revelation 21:19

The foundations of the walls of the city were adorned with all kinds of precious stones
Were adorned is κεκοσμημένοι [kekosmēmenoi] , perfect passive participle: having been decorated. She was adorned in the past in preparation for her husband. See commentary on Revelation 21:2.

O you afflicted one, tossed with tempest, and not comforted, behold, I will lay your stones with colorful gems, and lay your foundations with sapphires. I will make your pinnacles of rubies, your gates of crystal, and all your walls of precious stones. (Isa. Isa. 54:11-12)

There is some uncertainty as to the relationship between the names of the stones in the original languages (Greek and Hebrew) versus our modern equivalents. The interested reader is encouraged to refer to more extensive treatments concerning their identity in recommended reference works.1


1 [Geoffrey W. Bromiley, ed., International Standard Bible Encyclopedia (Grand Rapids, MI: William B. Eerdmans Publishing Co., 1979, 1915)], [Trent C. Butler, Chad Brand, Charles Draper, and Archie England, eds., Broadman and Holman Illustrated Bible Dictionary (Nashville, TN: Broadman and Holman Publishers, 2003)], [Merrill K. Unger, R. Harrison, Frederic F Vos, and Cyril J. Barber, The New Unger’s Bible Dictionary (Chicago, IL: Moody Press, 1988)], [Ronald F. Youngblood and R. K. Harrison, eds., Nelson’s New Illustrated Bible Dictionary (Nashville, TN: Thomas Nelson, 1997, c1995)], and [David Noel Freeman, ed., The Anchor Bible Dictionary (New York, NY: Doubleday, 1996, c1992)].