'Clear as Crystal' in the Bible

Also in front of the throne there was something like a sea of glass as clear as crystal. Around the throne, at the middle of each side were four living creatures dotted with eyes in front and behind,

and it continued to retain the glory of God. The luster of it was like a very precious stone, like jasper, clear as crystal.

Then he showed me a river of living water, clear as crystal, which continued to flow from the throne of God and of the Lamb