1: σάπφιρος
(Strong's #4552 — Noun Feminine — sappheiros — sap'-fi-ros )

is mentioned in Revelation 21:19 (RV, marg., "lapis lazuli") as the second of the foundations of the wall of the heavenly Jerusalem (cp. Isaiah 54:11 ). It was one of the stones in the high priest's breastplate, Exodus 28:18; 39:11; as an intimation of its value see Job 28:16; Ezekiel 28:13 . See also Exodus 24:10; Ezekiel 1:26; 10:1 . The "sapphire" has various shades of blue and ranks next in hardness to the diamond.