Revelation 4:6

also in front of the throne there is like a sea of glass, resembling crystal. And on each side of the throne, all round it, four living Creatures full of eyes inside and outside;

Revelation 5:6

Then I noticed a Lamb standing in the midst of the throne and the four living Creatures and the Presbyters; it seemed to have been slain, but it had seven horns and seven eyes (they are the seven Spirits of God sent out into all the earth),

Revelation 15:2

And I saw what was like a sea of glass mixed with fire, and, standing beside the sea of glass, those who came off conquerors from the Beast and his statue and the cipher of his name; they had harps of God

Revelation 7:11

And all the angels surrounded the throne and the Presbyters and the four living Creatures, and fell on their faces before the throne, worshipping God

Revelation 14:3

they were singing a new song before the throne and before the four living Creatures and the Presbyters, and no one could learn that song except the hundred and forty-four thousand who had been ransomed from earth.

Revelation 15:7

Then one of the four living Creatures gave the seven angels seven golden bowls full of the wrath of God who lives for ever and ever;

Revelation 19:4

Then the four and twenty Presbyters and the four living Creatures fell down and worshipped God who is seated on the throne, crying, "So be it, hallelujah!"

Revelation 4:8-9

The four living Creatures, each with six wings apiece, are full of eyes all over their bodies and under their wings, and day and night they never cease the chant, "Holy, holy, holy, is the Lord God almighty, who was and is and is coming."

Revelation 5:14-1

"Amen," said the four living Creatures, and the Presbyters fell down and worshipped.

Revelation 7:17

for the Lamb in the midst of the throne will be their shepherd, guiding them to fountains of living water; and God will wipe every tear from their eyes."

Revelation 21:11

with the glory of God. The sheen of it resembled some rare jewel like jasper, clear as crystal;

Revelation 21:18

The material of the wall is jasper, but the City is made of pure gold, transparent like glass.

Revelation 21:21

The twelve gates are twelve pearls, each gate made of a single pearl; and the streets of the City are pure gold, clear as crystal.

Revelation 22:1

Then he showed me the river of the water of Life, bright as crystal, flowing from the throne of God and of the Lamb

Treasury of Scripture Knowledge

Summary

And before the throne there was a sea of glass like unto crystal: and in the midst of the throne, and round about the throne, were four beasts full of eyes before and behind.

Bible References

A sea

Revelation 15:2
And I saw what was like a sea of glass mixed with fire, and, standing beside the sea of glass, those who came off conquerors from the Beast and his statue and the cipher of his name; they had harps of God

Crystal

Revelation 21:11
with the glory of God. The sheen of it resembled some rare jewel like jasper, clear as crystal;
Revelation 22:1
Then he showed me the river of the water of Life, bright as crystal, flowing from the throne of God and of the Lamb

The midst

Revelation 5:6
Then I noticed a Lamb standing in the midst of the throne and the four living Creatures and the Presbyters; it seemed to have been slain, but it had seven horns and seven eyes (they are the seven Spirits of God sent out into all the earth),
Revelation 7:17
for the Lamb in the midst of the throne will be their shepherd, guiding them to fountains of living water; and God will wipe every tear from their eyes."

Four beasts

Revelation 4:8
The four living Creatures, each with six wings apiece, are full of eyes all over their bodies and under their wings, and day and night they never cease the chant, "Holy, holy, holy, is the Lord God almighty, who was and is and is coming."
Revelation 5:6
Then I noticed a Lamb standing in the midst of the throne and the four living Creatures and the Presbyters; it seemed to have been slain, but it had seven horns and seven eyes (they are the seven Spirits of God sent out into all the earth),
Revelation 6:1
And when the Lamb opened one of the seven seals, I looked, and I heard one of the four living Creatures calling like thunder, "Come."
Revelation 7:11
And all the angels surrounded the throne and the Presbyters and the four living Creatures, and fell on their faces before the throne, worshipping God
Revelation 14:3
they were singing a new song before the throne and before the four living Creatures and the Presbyters, and no one could learn that song except the hundred and forty-four thousand who had been ransomed from earth.
Revelation 15:7
Then one of the four living Creatures gave the seven angels seven golden bowls full of the wrath of God who lives for ever and ever;
Revelation 19:4
Then the four and twenty Presbyters and the four living Creatures fell down and worshipped God who is seated on the throne, crying, "So be it, hallelujah!"

Full

Revelation 4:8
The four living Creatures, each with six wings apiece, are full of eyes all over their bodies and under their wings, and day and night they never cease the chant, "Holy, holy, holy, is the Lord God almighty, who was and is and is coming."