Also see definition of "Sapphire" in Word Study
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Sapphire
Sapphire [EBD]
Associated with diamonds (Ex. 28:18) and emeralds (Ezek. 28:13); one of the stones in the high priest's breastplate. It is a precious stone of a sky-blue colour, probably the lapis lazuli, brought from Babylon. The throne of God is described as of the colour of a sapphire (Ex. 24:10; comp. Ezek. 1:26).
Sapphire [NAVE]
SAPPHIREA precious stone, Job 28:6, 16; Isa. 54:11; Ezek. 28:13.
Set in the breastplate, Ex. 28:18.
The color of the firmament, Ezek. 1:26.
Seen in the foundation of the New Jerusalem in John's apocalyptic vision, Rev. 21:19.
SAPPHIRE [SMITH]
(Heb. sappir), a precious stone, apparently of a bright-blue color, set: (Exodus 24:10) the second stone in the second row of the high priest?s breastplate, (Exodus 28:18) extremely precious, (Job 28:16) it was one of the precious stones that ornamented the king of Tyre. (Ezekiel 28:13) The sapphire of the ancients was not our gem of that name, viz. the azure or indigo-blue, crystalline variety of corundum, but our lapis lazuli (ultra-marine).Also see definition of "Sapphire" in Word Study