Treasury of Scripture Knowledge

Summary

And the likeness of the firmament upon the heads of the living creature was as the colour of the terrible crystal, stretched forth over their heads above.

Bible References

The likeness

Ezekiel 1:26
Now above the expanse that was over their heads there was something resembling a throne, it appeared like [it was made of] sapphire or lapis lazuli; and [seated] on that which looked like a throne, high up, was a figure with the appearance of a man.
Ezekiel 10:1
Then I looked, and behold, in the expanse (firmament) that was over the heads of the cherubim there appeared something [glorious and brilliant] above them looking like a [huge] sapphire stone, formed to resemble a throne.
Exodus 24:10
and they saw [a manifestation of] the God of Israel; and under His feet there appeared to be a pavement of sapphire, just as clear as the sky itself.
Job 37:22

“Out of the north comes golden splendor [and people can hardly look on it];
Around God is awesome splendor and majesty [far too glorious for man’s eyes].
Revelation 4:3
And He who sat there appeared like [the crystalline sparkle of] a jasper stone and [the fiery redness of] a sardius stone, and encircling the throne there was a rainbow that looked like [the color of an] emerald.
Revelation 21:11
having God’s glory [filled with His radiant light]. The brilliance of it resembled a rare and very precious jewel, like jasper, shining and clear as crystal.