As opposed to other sedimentary precious opal, boulder opal is attached to the ironstone and stones are usually cut with the natural ironstone backing intact. Solid opals may be cut from the ironstone material where the opal is of sufficient thickness. Boulder opals are fashioned to standard shapes and sizes but are also cut in freeform shapes to highlight their individual beauty and to avoid wastage. Magnificent picture stones are also cut but these are mainly of interest to collectors rather than for jewellery use. The larger mines worked in recent years are large open-cut operations.
Overburden is stripped from zones of ironstone boulder concretions.
Boulders are carefully removed from the ground for processing. Heavy equipment has been used to open up most areas of old workings. Underground methods are still applied with success in some areas. Shafts are sunk until a prospective layer is intersected, rapid sinking of shafts being accomplished with Calweld bucket drilling rigs. If the boulders show any evidence of opalisation, they are first removed from the mined ground and collected up for later inspection for opal content and sorted in readiness for sale as rough or for further processing.