FUN FACTS ABOUT OPALS


Opal is a fascinating gemstone that has captivated people for centuries. It is best known for its dazzling play-of-color effects, ranging from soft pastels to electric hues. But there is so much more to opal than just its beauty! Here are some fun facts about opal that you may not know:


  • Besides being designated as October's birthstone, opal crystal is the official gemstone gift alternative for the 14th wedding anniversary.


  • Like every other precious gemstone, opal has an astrological planet linked with it. It's associated with Venus, and astrologers may recommend the opal gemstone for various reasons. Opal is commonly used to enhance the impact of Planet Venus in the wearer's astrology chart.


  • In astrology, the planet Venus is associated with luxury, comforts, love, romance, riches, and beauty in one's life. Opal gemstone's astrological benefits include boosting all of these areas of your life.


  • There are several claims about the origin of the word "Opal." One is that the name comes from the Sanskrit word "Upala," which means "valuable stone."


  • Some believe the word opal comes from the Latin word "opalus," which means precious stone.


  • However, others think it's derived from the Sanskrit word "úpala" meaning precious stone.


  • Opal gemstones form when water flows through rock crevices from heavy rains and slowly deposits silica (the main ingredient in sand) on top of other stones or fossils. These deposits form a thin layer of silica over the object that eventually becomes an opal, with brilliant color from the diffracted light projected through it.


  • Opal crystal is the national gemstone for Australia. Approximately 95 to 97 percent of the world's opal supply comes from the three regions: New South Wales, Queensland, and South Australia.


  • Other sources of natural opals include Brazil, Mexico, Hungary, the United States, Peru, Ethiopia, Nicaragua, and some other countries.


  • Opal color comes in two basic types: background color and play of color. Impurities cause the background color within the silica.


  • The play of color you see in opal crystals is due to millions of tiny silica spheres of different sizes in their internal structure. These tiny spheres refract light and cause beautiful spectral colors.


  • This can be almost any color; however, the most common opals are white, green, or translucent.


  • Common opal often displays a hazy-milky- turbid sheen from within the gemstone. In gemology, this optical effect is opalescence, a form of adularescence.


  • Black opals are one of the rarest gemstones, though they can be a variety of dark colors.


  • Most Australian opals are white opals found in Coober Pedy, South Australia.


  • Unlike many other gemstones on the market, opals are usually left in their natural state; however, some commonly used treatments are fracture filling and smoke treatment, which darkens the gemstone.


  • Once categorized, opal prices are determined by carat or weight. Because there are so many opal fields in Australia, there is no singular opal form. This means that opal prices can vary from $10 per carat to approximately $6,000 per carat.


  • Opal hardness ranges between 5.5 and 6.5 on the Mohs Scale of Hardness. This means opal hardness is very poor to fair, making opal a gem suitable for jewelry but which requires care when wearing to not scratch or break the stone.


  • Opal gemstones are amorphous and do not have a defined crystalline structure, unlike most gemstones; instead, it takes on many shapes and colors, and in that way, it is pretty unpredictable.


  • Natural opal consists of hydrated silica gel that contains as much as 20 percent water, which means it may dry out if left in a warm environment.


  • Opals come in various categories, including white, black, fire, crystal, and boulder opal.


  • Opal cabochon stones are either low, medium, or high domed. A high domed cabochon gives the opal more depth of color. Dark opals will predominately be low to medium dome cabochons. Dark opals are cut this way due to the thin concentration of color found within the raw material.


  • Crystal opal, also known as clear opal, is translucent: some light will pass through if you hold it up to the light. Clear opal crystal doesn't have a crystalline structure like amethyst or diamond – it's called 'crystal' simply because its translucency or transparency resembles crystalline materials such as rock crystal or glass.


  • Black opals are actually not black. Black opals have a natural backing to them called "potch" that gives them their dark body color.


  • Black opal stones display various colors, including yellow, blue, green, violet, fiery red, and orange. The more colorful the black opal stone, the more valuable it is.


  • Australian black opal stones from Lightning Ridge are highly esteemed and some of the most expensive opals available. Lightning Ridge black opals price can vary from roughly $30 per half a carat to $1,500 per carat. Lightning Ridge black opals price for gems weighing 5-10 carats can cost up to $50,000.


  • In the world of opals, harlequin opals are the one stone type that collectors, opal lovers, and miners all wish they could find. This is a scarce pattern; thus, harlequin opals are some of the most expensive opals. Some stones may contain just a tiny part of the opal in this pattern, but the pattern needs to encase the whole stone. If only one part of your stones have this pattern, they are not authentic harlequin opals.


  • This pattern has been unique to Lightning Ridge opal stones, and red fire is the rarest. Lightning Ridge opal stones with an n1 body tone with this pattern can be worth around $5,000 to $30,000 per carat.


  • Boulder opal is the only type of opal that contains all the colors of the rainbow within one stone and can cost up to $3000 per carat.
  • The Mexican Fire Opal is a brilliant red to orange body color partly due to iron oxide. Mined in Mexico, this Mexican Fire Opal is lighter weight than other opals. They tend to have one body color and do not usually contain the flashes of light and typical opal colors.


  • Mexican opal is the only natural opal gem that is usually faceted. Light and dark Mexican opal varies from bright orange to reddish-orange and is brilliant-cut with precise calibration.


  • Compared to black opal, fire opal is more affordable, with price points ranging from $70 per half a carat to $1,000 for 3.5 carats.


  • Andamooka is one of the oldest known opal fields in Australia.


  • The "Queen's Opal" is another name for Andomooka opal matrix. On the occasion of Queen Elizabeth II's first approved state visit to Australia, Andomooka opals were cut and set into an 18-carat palladium choker and handed to her. These Andomooka opals set in a necklace and earrings for her are now important pieces of Queen Elizabeth II's royal jewels.


  • Discovered in 1930, Andamooka is considered one of the most prominent opal fields. This Australian opal mine has generated some of the most attractive pieces or sets of Andomooka opals, such as "The Andamooka Opal Matrix," also referred to as "The Queen's Opal" mentioned above.


  • The Andamooka Australian opal mine is well-known for producing light opal stones, including white, crystal opal, known as "milk" opal.


  • The Andamooka matrix opal can be found only in the South Australia region. This particular kind of opal presents a porous host rock. The Andamooka matrix opal contains a conglomerate of sand and small grains of precious opal.


  • Andomooka opal can be treated with sugar to turn it black and improve the opal play of color.


  • Opals were particularly popular in the Art Deco era when gemstone artists preferred them to other stones.


  • In the Middle Ages, the opal was considered a stone that could provide great luck because it possessed all the virtues of each gemstone whose color is included in the color spectrum of the opal.


  • The most expensive opal is the "Olympic Australis," weighing 17,250 carats. This massive opal gem comes from Coober Pedy in South Australia and was valued at $1.7 million USD., making it the most expensive opal in Australian history.


  • The Virgin Rainbow is one of the world's rarest and most expensive opals. It glows in the dark. As it gets darker around the opal, the opal appears ever more vibrant. It's valued at over $1 million and owned by the South Australian Museum in Adelaide.


  • Ethiopian opal stones from the Wegel Tena mines in the Welo province of Ethiopia are high-grade and extremely valuable. Ethiopian opal stones often surpass the quality of those found in Australia and Brazil.


  • With the emergence of opal production in Wollo, Ethiopia, the supply of hydrophane opal has increased significantly. However, most of the supply from Wollo is hydrophane opal, which means it is porous enough to absorb water, much like a sponge.


  • Ethiopian opals are also called chocolate opals for their chocolatey color inside their nodule. Ethiopian opals are not only beautiful, but they generally cost less than similar-quality opals from Australia. 


  • The most common fake opal is the assembled stone. Doublets or triplets are not completely fake opal stones but rather a combination of both genuine opals & synthetic materials to give the impression of solid opal. Plastic, glass, and synthetic fake opal stones are also widespread. They can have a columnar structure or lizard skin surface texture, unlike genuine opals.


  • Natural opals are sliced and adhered to onyx and other gem material to give the illusion of a bigger, dark, more expensive opal. The "doublets" are more susceptible to harm if submerged in liquids for long periods.


  • Petrified wood has the same makeup as an opal, given they are both formed from amorphous silica, but not all petrified wood is opal.


  • The gemstone signifies hope, innocence, confidence, and purity. Opals also bring happiness and beauty to the wearer.


  • One common myth about opal is you need to soak your opal in water to prevent cracking. The water content in opal comes from the formation of the stone, with water molecules locked into tiny voids within the opal's crystalline structure. Soaking your opal in water will do nothing to increase the life of your opal.