Opal production has decreased over the last decade. Demand has risen. More people are working the opal fields with greater mechanisation. Opal is like other resources- we are exhausting the existing known supplies and hoping new strikes will be found. The mining of opal is done by individuals or syndicates- no large companies are mining any of the fields. Stockpiling of the gem therefore cannot occur: this means that prices are a true reflection of market demand.
Opal as an investment will be a very good investment. The value of these gems can only increase as the better quality stones are becoming rarer to find.