The existence of a large scale precious opal industry is unique to Australia. While gem quality opal has been found in many countries, there has only been any significant commercial production, and then only on a smaller scale, from Slovakia in the past, and Mexico and Brazil today. At least 80% of the world's production comes from Australia.

Production at a substantial level has been going on in Australia for more than 100 years, and the end is far from sight. Apart from the production from the five major producing areas, there are still very large areas of country around the borders of the Great Artesian Basin which must be regarded as prospective for opal. New fields are difficult to find, however, as the gemstone rarely shows any evidence of its presence at the surface.

Most of the exploration is carried out by the occasional miner risking a shaft or drillhole in areas in the neighbourhood of known fields. Mostly, however, miners prefer to dig in known opal-bearing areas.

Some larger companies have been set up to explore on a professional basis, analysing the geology of opal-bearing areas, extrapolating this data into new areas, and then systematically drilling. In some States even this has not been possible, as the mining laws for gemstones leases were designed to encourage small groups by limiting severely the size of the leases.

The value of the industry to Australia is difficult to assess accurately, as much opal is sold to buyers, many from overseas, on a cash basis, and is not recorded in the production statistics. The miner is thus able to avoid paying taxes on some of his production.

It can be argued that this is not too unreasonable, as his finds are sporadic. In some years, he may only produce a few thousand dollars worth of the gemstone, then in one year he might find, say, $100,000 worth. He feels that he should be able to average his income for tax purposes, as the Australian farmer is permitted to do.

The official production statistics are for those for rough opal, and do not give a real indication of the retail market value of the cut stones. The very high values for the top grades also make estimates more difficult.

In 1982, Barnes and Townsend (R0725) stated that:

At the other extreme, they state that: