Crystal zekukith, from zaakak, "to be pure." Job 28:17; "the gold and the crystal cannot equal wisdom." Glass is meant, some costly goblet composed of glass and gold, such as Wilkinson says the Egyptians made (Ancient Egyptians 2:61). Kerach, literally, ice, the ancients believing rock crystal to be ice intensely congealed. In Ezekiel 1:22, "the likeness of the firmament was as the terrible (rather Splendid, dazzling) crystal" (Revelation 4:6; Revelation 21:11).