Lexicon
hualos: a clear transparent stone, glass
Original Word: ὕαλος, ου, ἡPart of Speech: Noun, Masculine
Transliteration: hualos
Phonetic Spelling: (hoo'-al-os)
Short Definition: glass
Definition: glass, crystal, clear transparent stone.
HELPS word-Studies
5194 hýalos – glass. 5194 (hýalos) refers to any transparent substance (like crystal), i.e. "see-through stones." On both of its occasions in the NT, 5194 ("pure, transparent glass") refers to the New Jerusalem – "apparently a metaphor (personification) of all the glorified saints, serving as the eternal dwelling place of God" (G. Archer).
NAS Exhaustive Concordance
Word Originprobably of foreign origin
Definitiona clear transparent stone, glass
NASB Translationglass (2).