Historical:
Prospecting involved searching for surface 'floaters' which had been weathered out of the host rock.
 Rectangular shafts approximately 4ft x 2ft were dug using only short handled picks, shovels and crowbars.
 Once down to the opal bearing level a lateral tunnel called a drive would be gouged with the aid of a candle and waste dirt was winched to the surface in leather buckets using a windlass.

Modern:
Prospecting for traces of Opal is done by first random and then close pattern drilling with hydraulic 8 inch truck mounted augers where the dirt is sieved and inspected as it is brought to the surface.
 When indications are positive a man-sized shaft is sunk with a bucket drill (Calwell) to inspect the opal level and a decision is made to either proceed with underground mining or open-cut the deposit.

Underground:
Lateral drives are dug following the Opal traces with hydraulic or electric tools and machines such as jack-hammers and tunnelling machines and if necessary explosives.
 Waste dirt in lifted to the surface by winch, Yorke hoist, self tipper, bucket elevator or blower.

Open Cut:
Overburden is removed by bulldozer or equivalent sometimes requiring the use of explosives to penetrate the hard surface rock strata.
 When the Opal bearing level is reached it is either

• Broken up by ripping with the machine and inspected for pockets of Opal (eg Mintabie, Coober Pedy).
• Excavated and washed in large agitators before inspection for Opal 'nobbies' (eg Lightning Ridge).
• Excavated and then inspected for boulders containing Opal veins (eg Quilpie and Winton).