2 Bible Verses about Sea Of Glass

Then I saw what appeared to be a sea of glass mixed with fire; and, standing by this sea of glass, holding the harps of God, I saw those who had come victorious out of the conflict with the Beast and its image and the number that formed its name.

and in front of the throne is what seemed to be a sea of glass, 'resembling crystal, while within the space before the throne and round the throne are four Creatures full of eyes' in front and behind.