Revelation 4:6; Revelation 22:1

Revelation 4:6

6 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.

Revelation 22:1

1 And he shewed me a pure river of water of life, clear as crystal, proceeding out of the throne of God and of the Lamb.