Chrysoprase

Chrysoprase is a light green to appel-green variety of chalcedony.

chrysopras chrysoprase
Excellent chrysoprase from the Candala Chrysoprase Mine, Marlborough, Rockhampton Region, Queensland, Australia

Shop for chrysoprase

Origin of name: from Greek χρυσός chrysos, gold and πράσον prason, leek

Synonyms and trade names: Australian Jade

Can be confused with: dyed green quartz, as well as other minerals of similar colour like jade, aventurine quartz, amazonite, fluorite, serpentine and turquoise

Localities: less than 80 localities worldwide. By far the biggest and most important European locality is Silesia, Poland. Other localities of commercial importance are Australia, Brazil, Tanzania and the USA.

chrysopras chrysoprase schlesien silesiachrysopras chrysoprase brasilien brazil
Chrysoprase from Silesia, Poland (left) and Brazil

Chrysopras Rohstück aus Australien
Rough chrysoprase from Australia

Verarbeitung: Handling: sensitive to hydrofluoric acid only. Keep away from galvanic baths. Otherwise unproblematic

Gemmological Properties of Chrysoprase

Formula:
SiO2
Crystal system:
trigonal
Mohs hardness:
6.5-7
Specific gravity:
2.58-2.91
Refractive index:
birefringent 1.543-1.554, not quite as hard as macrocrystalline quartz, but much tougher
Max. Birefringence:
0.009
Dispersion:
none
Pleochroism:
none
Luminiscence:
none
Lustre:
waxy
Cleavage:
none
Fracture:
conchoidal, splintery
Colour:
light green to medium dark appel-green