Brazilian Opal Rough ,unlike Mexican opal rough there has never been lot opal rough available as most is cut in the opal fields or by opal miners themselves
Most are found in sandstone in quarry’s and are hand dug operations with pick and shovel.
Unlike Australian opal rough it is found in sandstone and siltstones as was washed down over the centuries by rivers
So this alluvial type opal is harder to mine in large scale operations
Brazilian opal is considered very stable and has white opal to fiery opal colours