'Crystal' in the Bible

In front of the throne was something like a sea of glass as clear as crystal. In the center of the throne and on each side of the throne were four living creatures full of eyes in front and in back.

The glory of God was its radiance, and its light was like a valuable gem, like jasper, as clear as crystal.

Then the angel showed me the river of the water of life, as clear as crystal. It was flowing from the throne of God and the lamb.