Topical Studies for Revelation 21:19:
Agate {Nave's Topical Bible}
Emerald {Nave's Topical Bible}
Jasper {Nave's Topical Bible}
Sapphire {Nave's Topical Bible}
Stones {Nave's Topical Bible}
Foundation {Forerunner Commentary}
Foundation {Torrey's Topical Textbook}