Opal is comprised of tiny silica spheres, formed when silica-rich water seeps into deep cracks and voids in the Earth's crust. It is separated into two groups, common opal (also known as potch) and precious opal (also known as noble opal).
Australia mines 97% of the world's different types of Opals. These include the stunning Black Opals, Boulder Opals, White Opals, Crystal Opals, and Opal Doublets and Triplets. These are made into beautiful varieties of opal rings, opal earrings, opal pendants and necklaces.
Opal has no crystal structure, and it is an amorphous form of hydrated silica. It comes in two forms, precious opal that displays the play-of-color phenomena, and common opal that does not.
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.
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.
It is these specimens that command exceptionally high prices. Your customers may also be familiar with black, or dark, opal, which has a dark body colour - sometimes enhancing the brilliance of the colours. This is the rarest and most valuable opal variety.
An opal imitation will often have an overly shiny appearance, and the colour flashes will be repeated in an organised pattern. Turn it side-on, and a columnar structure will be revealed to you. Real, natural opals possess irregularities, which adds to the stone's authenticity and beauty.
Opals that has not been changed from its natural state -- except to be cut and polished into a gem stone. The best know types are Queensland Boulder Opal, Black Opal, Crystal Opal, White Opal. Opal can also be found in Mexico and Ethiopia.
Black opal is the most rare and highly valued form of opal, and has what is called a black (or dark) body tone. Black opals come in every colour of the rainbow.
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.
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. White opals have a light body tone and are generally the least valuable form of opal.
Opals are well-known for their incredible play of colors and unique characteristics, captivating gem enthusiasts and collectors worldwide.
To start, look at the opal closely and examine its color, pattern, and brilliance. Real opals should have a uniform body color, often with a bright fire or play of color that flashes as it moves in the light. The opal colors can range from pale pink to vibrant blues and greens.
Opals have grades of below commercial, commercial, good, fine, and extra fine. These assessments cover an opal's colors, directionality of flashes, imperfections, and cut. Body tones, from N1 (black) to N9 (white), describe the base color of a stone, without play of color.
Hydrophane opals have the ability to absorb water or liquids, similar to a sponge, resulting in a change of color that may turn the opal translucent yellow or brown and the play-of-color to disappear temporarily. Don't panic though! The color will return once the opal is fully and naturally air-dried.
Durability. Perhaps the most significant difference between Australian Opals and Ethiopian Opals is that most Ethiopian Opals are hydrophane while Australian Opals are not. What does that mean? It means that Ethiopian Opals are hydrophilic (water-loving) and they will readily and readily absorb water.
Pricing. Current opal prices depend on the type of opal stone. The most valuable Opal, Black Opal, ranges from $50 per carat to $10,000 per carat. Alternatively, White Opal is relatively common and ranges from $10 per carat to $150.
Australian Opal Value Per Carat
Because there are so many opal fields in Australia, there really is no singular form of opal. This means that opal costs can vary from about $10 per carat to approximately $6,000 per carat.
Appearance. Australian Boulder opals are the second most valuable type of opal (following black opal).
Opals also have water content that may range from 3 to 21% by weight, so there's a possibility of them developing cracks if they get dried out. However, after considering everything, if you still wish to wear opals on an everyday basis, then you need to do so with extra care.
Australian opal is considered to be the most valuable of all types of opal thanks to its captivating play-of-colour, beautiful patterning and superior quality. It's ethically mined too.