Natural rough opal potch wood, which is also volcanic, is mined
in Indonesia, and it is olive green colour to brown hues and has no treatment.
Black volcanic Indonesian opal is mostly treated.
The opal miners wrap this opal in aluminium foil and then heat
to cook the opal and add oil, so the oil penetrates inside the specimen.
This cooking process also makes the sticky clay drop off the
This treatment is not permanent
These opal specimens do look attractive with glass vale
filled with glycerine to help enhance the colour
Our sellers from Indonesia will list in description if the
opal is treated.