John lists twelve precious stones. Striking is that the first stone he mentions is—again—jasper, the stone earlier mentioned as earth’s best comparison of God’s glory (Revelation 4:3; Revelation 21:11, Revelation 21:18). This first stone sets the tone and purpose of the remaining stones; they are all intended to convey something of the glory of the city (recall Revelation 21:11a) and so of the God who dwells in this city (and so of the people who may share his glory, Revelation 21:3). Though we may research a gemology textbook to obtain a sense of these jewels (though be aware that definitions may change over centuries!), we should bear in mind that the point is not so much the precise stone mentioned as the notion of glory; these are precious stones that communicate the honour befitting the Lord God.
19 The foundations of the wall of the city were adorned with every kind of jewel. The first was jasper, the second sapphire, the third agate, the fourth emerald,