Ezekiel 1:22

And there was a likeness over the heads of the living one - an expanse, like terrible crystal to look upon, -stretched forth over their heads above.

Ezekiel 10:1

Then looked I. and lo! in the expanses which was over the head of the cherubim as a sapphire stone, as the appearance of the likeness of a throne, appeared over them.

Ezekiel 1:26

And above the expanse that was over their heads, as the appearance of a sapphire stone, was the likeness of a throne, - and upon the likeness of a throne, was a likeness as the appearance of a man upon it above.

Revelation 4:6

and, before the throne, is as a glassy sea, like unto crystal. And, in the midst of the throne, and around the throne, are four living creatures full of eyes, before and behind;

Exodus 24:10

and they saw the God of Israel, - and under his feet, like a pavement of sapphire, and like the very heavens for brightness; and

Job 37:22

Out of the north, a golden light cometh, Upon GOD, is fearful splendour:

Revelation 4:3

and, he that was sitting, was like in appearance to a jasper stone and a sardius, and there was a rainbow round about the throne, like in appearance unto an emerald,

Revelation 21:11

having the glory of God, - her lustre, like unto a stone most precious, as a jasper stone, shining as crystal;

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
And above the expanse that was over their heads, as the appearance of a sapphire stone, was the likeness of a throne, - and upon the likeness of a throne, was a likeness as the appearance of a man upon it above.
Ezekiel 10:1
Then looked I. and lo! in the expanses which was over the head of the cherubim as a sapphire stone, as the appearance of the likeness of a throne, appeared over them.
Exodus 24:10
and they saw the God of Israel, - and under his feet, like a pavement of sapphire, and like the very heavens for brightness; and
Job 37:22
Out of the north, a golden light cometh, Upon GOD, is fearful splendour:
Revelation 4:3
and, he that was sitting, was like in appearance to a jasper stone and a sardius, and there was a rainbow round about the throne, like in appearance unto an emerald,
Revelation 21:11
having the glory of God, - her lustre, like unto a stone most precious, as a jasper stone, shining as crystal;