Many people wonder about the differences between Ethiopian opals and Australian opals.
You may often see large, beautiful Ethiopian opals that cost significantly less than smaller Australian opals and you could be wondering, why not get these….
There are several differences between the types of opals but the most important one to you as a customer is the porosity of the stone.
Opal stones are quite unique as they contain a relatively high amount of water which effects their translucency, their clarity, and their colors. Ethiopian opals have microscopical pores that are not visible to the naked eye but they allow the stone to absorb fluids and to be affected by the environment. This may not sound too bad but when you wear a piece that is set with opal against your skin it will absorb creams, fluids you come in contact with, sweat, etc which will change the general look of the stone. In severe cases, a wonderful, colorful Ethiopian opal may lose all it’s colors and turn a uniform, dull orange after a year or so of wearing it. The process is not really reversible even if you soak the stone in clean water and you may end up with an entirely different opal from the one you bought.
Australian opals have a sealed surface that does not allow it to absorb anything so it will stay as beautiful as the day you got it.
A simple test can reveal if your opal is porous or not, you would need a gemstone scales that can measure carat weight and a glass of water. Just take the stone when it is dry and measure the weight. Place it in a glass of clean water for 24 hours and then weight it again, if the opal gained weight it is porous, if it did not you can safely say it is sealed and will not change over time.
Opals are not cheap either way you look at it so if you are getting an opal it is strongly recommended to get an Australian opal for your peace of mind.
How to care for your opal
Opal stones are beautiful but they need to be handled with care if you want to enjoy them for years.
The most important thing to remember when you own an opal is that they are very delicate. If an opal is hit directly by a hard object it can easily chip or break so the most important rule is to take of your opal jewelry before performing any rough activity.
Cleaning your opal can be done by leaving it for several minutes in a bowl of hot water with strong soap and then gently scrubbing it with a soft toothbrush. If you own an Australian opal you can do almost anything with it except exposing it to intense heat or rough impact.
If you opal has chipped or broke you may be able to polish it and still use it depending on the location and sort of damage it took, it is worth consulting with an expert in such cases before rushing to replace your opal.
How much an opal is worth?
Many people wonder how to evaluate the price of opal and it is indeed a complex matter. There are so many criteria that determine the value but in general, the better looking and larger the opal the more expensive it is.
Size – Like most gemstones, the size is an important factor… the larger the opal the more expensive it is. Opals are priced per carat and the larger the opal the higher the price per carat so the price grows significantly.
Matrix – There are many types of opals but the most popular ones are white/crystal opals and black opals. The cause to the color definition of an opal is the color of the matrix that composes the opal. that can be milky white/translucent or dark/black. In general dark/black opals cost significantly more than the white/crystal ones. The darker the opal the higher the price.
Colors – As colors are what makes opals so beautiful they have a major impact on the price. The more intense the colors (color intensity grading is known as brightness) the higher the price. Some opals may reveal faint colors in very specific angles while others will show very strong colors in many angles, the latter or more valuable. The presence of certain color also changes the price… while blue and green are more common in opals you can sometimes see reds and oranges in opals which raises the price significantly.
Pattern – The array of colors on opal stone is known as a pattern, there are many different patterns you can find and some are very rare. Common patterns or unclear patterns would cost much less than rare patterns and very distinct patterns.
Shape – The way an opal is cut also has a major impact on the price. Regular cuts like oval, round, and pear shapes cost much more than irregular shapes like baroque and different sorts of shapes. If you care more about the quality of the material than the shape you can consider irregularly shaped opals to get higher quality material for your budget. The thickness of the stone is also important as a high or medium domed opal is not only better looking than thin or flat cut opals but it is also more durable… If a thin opal gets hit there is a much higher risk of significant damage than if a thick opal is hit.
There are more factors that influence the price like the stone’s origin in Australia, the presence of rock in the stone, and more but the above criteria are the most important.
When shopping for an opal it is best to define a budget and anchor characteristics that are most important to you. This will help you narrow down your options and find the best opal for your budget.
I am a designer and architect. Graduated at the Technion, Israeli institute of technology.