(χρυσόλιθος, Revelation 21:20)
In modern usage the name ‘chrysolite’ is applied to a transparent variety of olivine, used as a gem-stone and often called ‘peridot.’ The ancients applied the word to various yellowish gems. The Septuagint gives it as the equivalent of תַּרְשִׁישׁ, which Flinders Petrie (Hasting's Dictionary of the Bible (5 vols) iv. 620b) is inclined to identify with yellow jasper. The later Greeks gave the name chrysolite to the topaz, which was unknown in earlier times.
James Strahan.