44 Grk “and its wall”; the referent of the pronoun (the city) has been specified in the translation for clarity. Here καί (kai) has not been translated because of differences between Greek and English style.
45 The phrase ἡ ἐνδώμησις τοῦ τείχους (hē endōmēsis tou teichous) is difficult to translate precisely. ἐνδώμησις states, “primary mng. ‘interior structure’; in our lit. prob.=construction, hence material τοῦ τείχους Rv 21:18.” The phrase could then be translated, “the foundation of the city wall was jasper” or “the material used for the wall of the city was jasper.” The latter alternative has been used in the translation because the text goes on to discuss the foundation in 21:19 (using the term θεμέλιος [themelios]), which is somewhat redundant if the foundation is mentioned here.
46 Or “transparent crystal.” See L&N 6.222, which notes the emphasis is on transparency here. The same Greek word, καθαρός (katharos), means both “pure” (referring to the gold) and “transparent” (referring to the glass).

In other versions

The wall was built of jasper, while the city was pure gold, like clear glass.

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

The building material of its wall was jasper, and the city was pure gold clear as glass.

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

And the material of its wall is jasper, and the city is pure gold, similar in appearance to pure glass.

And the building of the wall of it was of jasper: and the city was pure gold, like unto clear glass.

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