PINK OPAL -AUSTRALIA

This is a natural untreated stone well polished and ready for setting. It has interesting white potch lines in it

This is what the West Australian mine dept says about Pink Opal

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Pink opal
‘Pink opal’ is a prospectors’ name applied to a different
variety of mookaite that outcrops as a persistent bed of
extremely bright pink opalized radiolarite near Binthalya.
At this site, pink opal is present as a dominant, horizontal
bed within zones of coloured porcellanites located beneath
a surface-brecciated zone in which angular fragments of
pink porcellanite have been cemented by iron and silica
solutions to produce an attractive pink breccia. The pink
zone beneath has already been tested by trial mining to
ascertain the extent and consistency of the pink, opalized
material.

Examination of pink opal thin sections has confirmed
the rock is radiolarite with a dominantly isotropic, finegrained
mineral composition. Although not verified by
XRD analysis, the pink opal’s physical and visible optical
properties suggest it is predominantly opaline silica,
having a lower bulk density than the locally porcellanized
mookaite material. Pink opal commonly shows liesegang
banding and often contains small vugs and fine fractures
infilled with microcrystalline quartz. Microscopic,
lustrous grains within the rock result from reflections of
granular quartz where it has infilled pores and replaced
radiolarian structures.
In a manner similar to the origin of mookaite, the resilicification
of the Windalia Radiolarite forming the pink
opal porcellanite has resulted in a visually attractive, bright
pink material displaying a high vitreous lustre. Pink opal
is extremely hard and brittle with a conchoidal fracture
. These properties allow pink opal
to take a high polish, making it suitable for the production
of colourful, polished tumbled stones, cabochons, and
other artworks .

All weights and sizes below are approximate