The mineral chrysoprase a type of chalcedony, which is a cryptocrystalline variety of quartz.
Minerals described as cryptocrystalline have crystals that can only seen when magnified.
Chrysoprase is known for its spectacular green colour. The finest grade gemstones can be mistaken for emeralds.
The colour of chrysoprase comes from impurities of nickel.
Chrysoprase was mentioned by ancient Roman author and naturalist Pliny the Elder in his encyclopedia Naturalis Historia.
The Chapel of Saint Wenceslas in Prague is decorated with chrysoprase.
Minerals: B
