When opal miners have to work underground in search of seam opal(those mines at Lightning Ridge, Coober Pedy and Andamooka) a miner will stake his (or her) claim, secure the funding needed to purchase the appropriate equipment, and then sink a shaft some 40 feet down. With this shaft as a base, they will then tunnel horizontally outward in search of opal.

Until the 1970s, the miners would tunnel outward using hand tools. Nowadays an auger is used. An auger is a giant drill which can bore a circular tunnel in a matter of hours.

One the tunnels have been made, various equipment is lowered down, depending on how much funds the miner has. Black opal mines typically use quite a bit of expensive equipment, as black opal is the most lucrative opal to mine.

Claims are granted in either 50- or 100-meter lengths. Miners typically have not kept accurate maps of their tunnels, and on occasion heavy earth movers moving topside have actually fallen into tunnels below!

Opal mining, therefore, is a dangerous business, for a variety of reasons.