Revelation 21:21
And the twelve gates were twelve pearls; every several gate was of one pearl: and the street of the city was pure gold, as it were transparent glass.
Cross-reference
Revelation 21:11 describes the city's glorious light like jasper, which is the source of the splendor seen in the pearl gates and gold street here.
In Revelation 21:12, the twelve gates are named after Israel's tribes — these same gates are the pearl gates here, linking the city's entrance to the covenant people.
Revelation 21:18 says the city itself is pure gold like clear glass — the street of gold here matches that description of the city's material.
Revelation 17:4 describes the harlot Babylon adorned with pearls and gold — contrasting with the holy city's pure pearl gates and transparent gold street.
Revelation 18:16 describes Babylon's luxury with pearls and gold — contrasting the holy city's pure and transparent versions of the same.
Revelation 22:2 refers to the same street of the city — the gold street here is where the tree of life and river of life are located.
Ezekiel 48:31 provides the OT blueprint of twelve gates named after Israel's tribes, which Revelation adapts for the New Jerusalem's pearl gates.
Isaiah 60:17 promises gold instead of brass in Zion — the New Jerusalem's gold street fulfills that prophecy of abundant precious materials.
Matthew 13:45 compares the kingdom to a merchant seeking fine pearls — the pearl gates here symbolize the priceless entry into that kingdom.
Matthew 13:46 describes selling all for one pearl of great price — the single pearl gates echo the supreme value of entering God's presence.