Used by both the Greeks and Romans as a decorative stone, chrysoprase, a trans-lucent, apple-green stone is the most valued variety of chalcedony. The color, derived from the presence of nickel, may fade in sunlight, and stones may then he confused with fine jade.

Mines in Poland and Czechoslovakia once produced very line chrysoprasc. However, since 1965 the best- quality material has come from Queensland (Australia). Other localities are the Urals (Russia), California (USA), Brazil, and Austria.

Another green chalcedony, parses, has a more somber hue and is very rare.