There is no governing body which has sent the prices for opal; they are the result of what the international market is prepared to pay in order to obtain the gem. As with any other commodity, opal is subject to the laws of supply and demand. The supply opal is never guaranteed – the lack of the miner, variable costs, new discoveries, floods and weather conditions – all affect the supply of the stone. Demand relates to the enthusiasm of the customer for opal, and may be influenced by the world economy, fashion, and market trends.
Unprecedented demand over the last three decades for fine quality opal has caused prices to soar. Prices of fine quality black opals rival those of diamonds.
The attractiveness and appeal of a particular opal are the factors that are important at the final point of sale. It is important to determine the type of opal. For instance, a darker boulder opal my produce a similar colour display to a black opal, or sometimes even better play of colour; in this case the boulder opal can be more expensive than the black opal. When you are valuing an opal, the first thing to look at is the brilliant of colour as well as the play of colour.
The main types of Australian opal are depicted below. Black, Boulder, Boulder matrix and light opal are all natural forms. Treated Andamooka matrix opal is subjected to solutions of sugar and sulphuric acid to darken the body tone and enhance the colour. Composite opals, such as doublets and triplets, contain slices of opal cement to other materials. The manmade opals are more likely souvenirs for tourists to bring back home. As a piece of fine Jewellery, people often go for a solid opal as you will have lifetime wear out of it and it will become a family heirloom.
If you are after a solid Opal stone in Sydney, you need visit Cosmopolitan Jewellers. The Finest Opal Jewelry Store in Sydney (Opal Shop Sydney) located at The Rocks specializing in Australian Solid Opal Jewellery (Black Opals, Boulder Opals and Crystal Black), Australian South Sea Pearls, Pink Diamonds and Customized jewellery including Opal Jewellery (Opal Rings, Opal Pendants, Opal Earrings Sydney) and Pearl Jewellery.