G2930–κρύσταλλος–krustallos

and before the throne, as a glass sea, like crystal. And in the midst of the throne, and around the throne, four living creatures, full of eyes, before and behind;

κρυστάλλῳ, krustallō “as crystal,”

And he shewed me a river of water of life, bright as crystal, going out of the throne of God and of the Lamb.

κρύσταλλον, krustallon “crystal,”