John's vision of the New Jerusalem includes emerald as the fourth foundation stone (Revelation 21:19). The noun σμάραγδος designated high-quality green stones, especially emeralds, prized throughout the ancient world for brilliant color. The twelve foundations, each adorned with different precious stones, symbolize the twelve apostles and the glory of God's eternal city. Emerald's inclusion among jasper, sapphire, chalcedony and other gems creates a vision of overwhelming beauty and value. The foundations' diversity suggests completeness—every kind of precious stone contributes to the city's splendor.