What does Revelation 21:19 mean?
As verse 14 points out, New Jerusalem's wall has twelve foundations on which are inscribed the names of the twelve apostles. Verse 19 describes these foundations further as adorned with every kind of jewel. The foundations, therefore, are extremely beautiful. This begins the list of jewels that adorn the twelve foundations.The first jewel is a jasper, probably a crystalline red. This jewel is also mentioned in Exodus 28:20 as one of the twelve jewels placed on the breastplate of Israel's high priest. In Revelation 4:3 jasper is mentioned in connection with the appearance of the one John saw seated upon the throne. Revelation 21:18 informs us that the wall of New Jerusalem is constructed of jasper. Sapphire, agate, and emerald are also listed in Revelation 21:19. These jewels also adorned the high priest's breastplate (Exodus 28:18, 19). Sapphire is the blue of lapis lazuli. Agate is perhaps blue quartz with stripes. Emerald is green.