Glass

Glass was known to the Egyptians from at least 1500 B.C. and to the Phoenicians, who are credited with developing the blowpipe technique. In ancient Israel, glass was a luxury item used for small vessels, ornaments, and inlay work. The Hebrew word zekukith (Job 28:17), comparing gold and glass as items of great worth, is one of the few direct OT references. In the New Testament, the sea of glass before the divine throne in Revelation (Rev. 4:6; 15:2) conveys transcendent purity and calm. The mirror metaphor — seeing "through a glass, darkly" (1 Cor. 13:12, KJV) — refers to ancient polished-metal mirrors, not transparent glass, but the image communicates the partial, indirect nature of present spiritual knowledge contrasted with the full clarity of the eschaton.