Chrysoprase is cryptocrystalline, which means that
it is composed of crystals so fine that
they cannot be seen as distinct particles under
normal magnification. This sets it apart
from rock crystal, amethyst, citrine, and
the other varieties of crystalline quartz.
Other members of the cryptocrystalline silica family
include agate, carnelian, and onyx.

Unlike many non-transparent silica minerals,
it is the colour of chrysoprase, rather than any
pattern of markings, that makes it desirable.
The word chrysoprase comes from the
Greek χρυσός chrysos meaning 'gold'
and πράσινον prasinon, meaning 'green'.

Unlike emerald which owes its green colour to the
presence of chromium, the colour of chrysoprase is due
to trace amounts of nickel compounds in the
form of very small inclusions. The nickel reportedly
occurs as different silicates, like kerolite or pimelite
(not NiO mineral, bunsenite, as was reported before).
Chrysoprase results from the deep weathering
or lateritization of nickeliferous serpentinites or
other ultramafic ophiolite rocks. In the Australian
deposits, chrysoprase occurs as veins and nodules
with brown goethite and other iron oxides in the
magnesite-rich saprolite below an iron and silica cap.

CHRYSOPRASE ROUGH FOR SALE