All opal is an almost magical gem. The way it glitters in the light has an almost fairy-tale feel when you see a truly gorgeous stone. The amazing nature of the stone combined with the premium prices attracted by top specimens, unfortunately also attracts sellers anxious to make the top dollar without going through the effort of cutting or acquiring top products. How do you, the buyer, decide on where and what to buy? How can you spot the real article as opposed to a fake or lesser type? here is a helpful guide, assisted by respected industry leaders who have graciously allowed me to use some of their materials in order to help you make the most informed decisions on the best quality or value opals.
What kinds of opals are there on the market?
There are literally hundreds of different opal types on the market. In order to make an informed decision, however, it is possible to narrow down the vast variety of different opal types into two categories which will greatly assist you in assessing the quality of an opal. These two categories are: Treated or untreated and Country of origin
Treated vs untreated
Opals can be treated in a variety of ways. Basically this treatment can be broken down into colour enhancement and stabilisation. Colour enhancement is using smoking, dyes or chemical treatment to artificially darken the stone, thus enhancing its colour. Stabilisation is using external materials to enhance the strength, size or colour of the stone. The easiest treatment to detect is the doublet or the triplet. These are stones that have a thin section of precious opal glued onto a piece of common opal or rock. Here is a video from Riley Gunn, a well known supplier of opal on the doubleting method:
Here is a well known YouTube channel- Roy's Rocks demonstrating how to spot a doublet:
As with most of the things mentioned here, there is nothing inherently wrong with treating a stone, in fact for certain types of stone, treatment is the industry standard. if a stone is treated however, the seller should explicitly state that the product you are buying is a treated stone. This gives the consumer the freedom to make their own choices on the opals they buy.
Country of origin
All opal is special in its own way, and certain regions are known for certain types of opal. The international trade of opals all around the world is a good thing and should be encouraged. Its only when people are deliberately mislead about the origin of their opals, that issues of country and production emerge. Deceptively marketed opals do damage to both the consumer and the legitimate producers of all opals. If, for example an Ethiopian opal is marketed as Australian, the deception damages the reputation of both countries. Ethiopian opal being a beautiful stone in its own right merely being seen as a fake, and the good properties of quality Australian opals brought into question by mis-marketed stones that don't add up to expectations.
Ethiopian opal
The most commonly substituted opal is Ethiopian opal. The basic reason for this is that a huge deposit of cheap opal has been discovered in Ethiopia. It is therefore very tempting for agencies to market this cheaper opal as Australian, Mexican or other varieties. The basic test for Ethiopian opal is to wet the stone. As this kind of opal is Hydrophane, It will typically soak up moisture and go clear.
Photography:
we all to a certain extent put some effort into the presentation of our opals, but not to the extent that the opal is misrepresented. There are many hacks that can be applied to images to make opals appear better than in real life. Rather than presenting a few paragraphs on the topic, I'll let an expert, Riley Gunn explain it on his video:
Conclusion:
It is my hope that people can trust online sellers to do the right thing and sell, more or less what they say they are selling. These few tips should help the new opal buyer to navigate some of the hazards should a merchant be less ethical. Have a nice day!