ὕαλος

glass

Definition

ὕαλος refers to a transparent, glass-like material, specifically a clear, crystalline substance. In the New Testament, it describes the brilliant, translucent building materials of the New Jerusalem. In Revelation 21:18, the city's wall is said to be built of 'jasper, clear as crystal' (διαφανής ὡς ὕαλος), emphasizing its purity and radiance. In Revelation 21:21, the street of the city is described as 'pure gold, like transparent glass' (χρυσίον καθαρὸν ὡς ὕαλος διαυγής), highlighting its flawless, luminous quality. The word conveys the ideas of clarity, brilliance, and preciousness.

Biblical Usage

This word is used exclusively in the Book of Revelation (Revelation 21:18, 21:21) within visionary descriptions of the heavenly city, the New Jerusalem. In both occurrences, it functions in a simile ('as glass' or 'like transparent glass') to describe the astonishing purity and radiant transparency of the city's divine construction materials—the wall and the street. The usage pattern is entirely apocalyptic and symbolic, serving to depict the otherworldly splendor and perfection of God's eternal dwelling.

Etymology

Derived from the ancient Greek word ὕαλος (hyalos), which originally referred to a transparent, glass-like stone or crystal, and later to manufactured glass. It is the root for modern scientific terms like 'hyaline' (meaning glassy or transparent). The word's core meaning of a clear, see-through substance remained consistent from classical through Koine Greek.

Semantic Range

ὕαλος is theologically significant as it contributes to the imagery of divine perfection and holiness in the New Jerusalem. Its use underscores the purity, glory, and unblemished nature of God's eternal kingdom. The transparency of the materials symbolizes the absence of anything hidden, shameful, or impure (Revelation 21:27), reflecting God's own luminous holiness. Understanding this Greek term enriches the reading of Revelation by emphasizing that the city's beauty is not merely decorative but a manifestation of God's flawless character.

In the 1st-century Greco-Roman world, large sheets of clear, transparent glass were rare and valuable luxury items. 'Glass' (ὕαλος) more commonly referred to smaller decorative objects, vessels, or mosaic tiles. The biblical imagery of entire city structures made of material 'like transparent glass' would have sounded fantastically extravagant and divinely wondrous to the original audience, far surpassing any human architectural achievement.

κρύσταλλος (krystallos, G2930) — This word specifically means 'ice' or 'rock crystal,' a naturally occurring, clear quartz mineral. It is used alongside ὕαλος in Revelation (e.g., 4:6, 22:1) to describe similar brilliant, transparent substances in heavenly visions, with a possible nuance of solid crystalline structure.

Word Details

Scripture References