Boulder Opal Sets are mostly opals that have been cut from
the same rock and have the same matching colours or patterns and are ideal for
making matching opal jewelry.
Boulder opal can be split in two or more pieces and is the
only opal field where you can do this to opal
This was the opals may be large, but match with similar veins
or color bars and density.
The opal is cut depending if the opal color bar is horizontal
or vertical or if just skin-deep colour
Koroit and yowah have deep dark chocolate brown colour with infusions
of colours or different tones brown from chocolate to soft tans and caramel