Sedimentary (most Australian) opals have significantly lower water content than volcanic (most Ethiopian) opals, so they are more durable.
Given consideration alone, Australian Opals are more durable and wearable than their Ethiopian counterparts — in that you don't have to worry about water or the stone against your skin potentially altering the gem's play of color.
It might seem a tad bit odd, but Ethiopian opals are cheap because they don't control the market. Sure, they are a bit rarer than Australian, but they have to compete with opal royalty. The only way Ethiopian opal sellers can turn a profit is if they offer their gems at a lower price point.
Ethiopian opals are primarily formed in volcanic rock which is why they are also known as "volcanic opals." They are typically lighter in color than Australian opals, with a greater range of colors and patterns.
Australia is regarded as the world's leading source of opal and of the world's finest opal. In 1994, opal was declared Australia's National Gemstone. Opal is found in several other countries including Brazil, Mexico, Ethiopia, the United States, Canada, Peru, Indonesia, Honduras, Slovakia and the Czech Republic.
In summary; Black opals are the 'Rolls Royce' of opals, and often have a certain price attachment associated with their status and rarity. Black opals are generally considered to be the best in the world due to their dark body tone.
Black opal is the most prized opal and may realise prices over AUD $15,000 a carat. Boulder opals also have a dark body tone.
When you purchase opals for investments, these will come with a certificate of authenticity. Because these gems are rare, they are excellent items for a long-term investment. These are also stunning gemstones that you will want to admire frequently.
Ethiopian opal's value varies based on its variety, color intensity and patterns. Ethiopian opal specimens can sometimes be much larger than Australian opal stones, and they are also somewhat more durable and less prone to losing their water content (all opal contains a certain percentage of water).
Ethiopia vs Australia
Today, we have one of those unique opportunities to buy extraordinary opal from Welo, Ethiopia, discovered in 2008. The quality is finer than any I have purchased from Australia, up until now considered to be the finest opal source.
Does Ethiopian Opal turn yellow? If Opals are left in water and allowed to soak it up, they may lose their fire temporarily and turn yellow or brown. Don't worry, the fire and color will come back once the Opals have fully dried, which can take a few minutes to weeks, depending on how much water they managed to absorb.
Keep Opals Away From Water! Ethiopian Opals are "hydrophane", this means that they absorb water and when they do their appearance changes. If the Opals come in contact with water, they will soak it up it like a sponge.
Internal stresses arise upon any dehydration resulting in surface shrinkage and progressive crazing and cracking. These defects make many Ethiopian opals unsuitable for use in jewelry.
The benefit of Ethiopian Opals being hydrophane, is that unlike many other types of opal that are prone to drying out and crazing, Ethiopian opal does not really suffer this particular issue.
It is known to possess the virtues of all the gemstones on the spectrum of colours that it displays. The Opal gemstone is particularly favourable for the Taurus (Vrish) and Libra (Tula) zodiac signs. It bestows beauty, confidence, good health, opulence, and love on the wearer.
This is the most important thing to keep in mind when taking care of your Ethiopian opal jewelry (especially opal rings). Remove your opal ring when washing your hands, cleaning dishes, taking a shower, relaxing in hot tubs or Jacuzzis or going swimming.
Opals Have a High Water Content
If they dry too quickly they may indeed crack. This is also known as "crazing." That's why they're sometimes kept in water until they can be sold. It relieves the merchant of the responsibility. This is also a way to hide flaws.
The variety of types of opal means the cost can vary from about $10 per carat to approximately $6,000 per carat. At $1 million, the 'Virgin Rainbow Opal' is the world's most valuable Australian opal. It was discovered in 2003 by miner John Dunstan in Coober Pedy of Southern Australia.
Solid opals have traditionally been considered the best investment. However, the popularity of opal doublets has risen over time due to their affordability and the elevation of competition. The major difference between valuing an opal and a diamond is that there is no precise dollar to carat systemisation for opals.
The “Olympic Australis” is reported to be the largest and most valuable gem opal ever found. It was found in 1956 at the famous “Eight Mile” opal field in Coober Pedy, South Australia. A miner working his claim found the opal at a depth of 30 feet.
Of all the opal types, Australian black opal is the rarest and the most coveted among precious stone collectors. But even with all the knowledge we have of opal formation and play-of-colour, there's still much to learn and rediscover about this remarkably iridescent gem.
Among these alluring gemstones, there exists one that truly stands out for its magnificent appearance and rarity, earning the title of the most beautiful opal in the world: the Virgin Rainbow.