London Blue Topaz and Diamond Halo Ring Blue Topaz 3.8 ct. Diamond 0.43 ct. 18K White Gold Other Products. Eternity Ring Diamond 0.44 ct. 18K White Gold More Detail Diamond Halo Earrings 18K White Gold More Detail Diamond ring Diamond 0.07 ct. 18K White Gold More Detail Etenity Ring Diamond 1.07 ct. 18K White Gold More Detail