Underground mining as described previously is a method of drilling, blasting and removing overburden from a mine, while looking for pockets of opal. If your claim is partially pegged over an open cut mine, it is possible to drive straight in on the opal bearing level from the side of the cut. Before starting underground mining, it is a good Idea to do some drilling first in the hope of drilling traces of opal. If opal is drilled, it is then possible to drive underground to where the opal was drilled. There are a number of drills in and around Mintabie and most are available for hire. It is an advantage if you have a claim near an open cut mine, because drilling can commence near the edge of the cut, and proceed in lines working away from the edge. If opal is drilled close to the open cut, the opal can be recovered quickly. Drilling is the preferred way of testing claims before mining commences.