Glass

And before the throne was something like a sea of glass, as clear as crystal. In the center, around the throne, were four living creatures, covered with eyes in front and back.

And I saw something like a sea of glass mixed with fire, beside which stood those who had conquered the beast and its image and the number of its name. They were holding harps from God,

The wall was made of jasper, and the city itself of pure gold, as pure as glass.

And the twelve gates were twelve pearls, with each gate consisting of a single pearl. The main street of the city was pure gold, as clear as glass.