Throughout history, the opal gemstone has fascinated people across civilizations with its precious array of rainbow colors. In fact, ancient Romans valued the stone above all other gems. References to the gemstone are made long before the rise of the Roman Empire and can be found in Sanskrit literature about 1,000 years BCE. Legends and lore surround the stone, and opal is believed to have an array of healing properties. Today, it’s the official gemstone for individuals born in the month of October.
The word opal traces its origins to the Sanskrit word upala, which means valuable stone. The opal gemstone is believed to have been cultivated as early as 4,000 years ago with the first references to the stone documented in Sanskrit literature. According to ancient Greek legend, the stone is believed to be the tears of Zeus, which made the gem extremely valuable. Moreover, wearers of the stone were believed to receive the gift of foresight, which guaranteed success in wealth and war. On the isolated Australian continent, Australian aborigines also prized the stone. Due to its color play, aborigines believed that Opal was caused by the Creator – as he walked along a rainbow road, the left over stones from that road resembled rainbows. In medieval times, the stone became so valued that it began to rival diamonds. To combat this fashion craze, diamond merchants began to spread word that the stone was bad luck. To fight this superstition, Queen Elizabeth II wore the opal gemstone, which helped it regain popularity.
Opal is a gemstone that is classified as a mineraloid, and the most common types of rocks where opal can be found are limonite, sandstone, rhyolite, marl and basalt. Opal is known for its play of color, meaning that it appears to shimmer with different colors when viewed from various angles. This play of color is often confused with opalescence, but opalescence only describes the milkiness of some common forms of Opal – play of color is its own distinguishing feature, and the are separate characteristics.
Different types of opal are claimed to have different healing powers. For example, Australian opal, which comes in varying shades of blue, is believed to provide wearers with enhanced communication skills and can be a great assistance to public speakers. It’s also believed that opal can help wearers find their true love and can combat depression. Finally, opal is believed to accentuate the positive attributes of the zodiac sign that wearers were born under.
There are many different varieties of opal including but not limited to black, white, boulder, crystal, and fire. Opals are often separated in two broad categories, common and precious, and Precious Opals are largely those that exhibit good play of color. 97 percent of all of the world’s opal comes from Australia and it’s the country’s national gemstone. Below we’ll outline some of the major Opal varieties.
Boulder Opal is the second most valuable form of Opal after Black Opal, but is actually rarer than its more prized counterpart. It is often found in ironstone boulders, hence the name. When Boulder Opal Gemstones are cut, they often include some of the ironstone they originate from. The dark brown or grey color of the Boulder Opal allows it to better showcase its excellent color play effect, which is generally seen as the chief attraction of Opal gemstones. Boulder Opal can be difficult to cut into exact shapes, which is why it is often found in irregular shapes in the gemstone market. Due to the fact that Opal gemstones often contain ironstone, they can be more durable than other forms of Opal, which are generally quite soft compared to most other jewelry appropriate gemstone types. The most common vessels for Boulder Opals is in pendants and earrings – the gemstones are often cut irregularly and that can make them more difficult to put to use in rings and bracelets.
Fire Opal is the red-headed stepchild of the Opal family – it is one of the few varieties of Opal that are popular despite showing little color play. Instead, it is valued for its intense and lively orange-red color, which resembles its namesake. Fire Opal also often displays some level of transparency, which is another difference between the gemstone in question and most other varieties of Opal. While (as we mentioned earlier) most Opals are sourced from Australia, Fire Opals mostly come from Mexico and are often linked with the country. Generally speaking, the more intense orange and red colored stones are more sought after than the yellower varieties. Fire Opals, like most other Opals, are quite soft and are more suitable for jewelry types that sustain less wear-and-tear; for example, earrings and necklaces are preferable to rings and bracelets. If you have a Fire Opal handy, try taking it out with you to watch a sunset or sunrise – as the sun hits the horizon, the effect on the gemstone can be quite stunning.
Black opals from Southern Australia are the most expensive variety of the Opal family. The dark profile of the stone can enhance the play of colors effect and lead to a dazzling array of colors. Black Opals are probably the most valuable variety thanks to the fiery shimmer of the play of colors that it often exhibits. Contrary its name, Black Opal isn’t always black – the body of the gemstone itself can range from dark brown to black. Since the play of color of this stone can be enhanced synthetically, it is best to be sure of the supplier and their reliability before purchasing, particularly if the stone exhibits too much of the famed play of color effect or is appears totally without flaws.
Also known as Light Opal, these stones are typically lighter colored and exhibit less play of color than the more valuable Black Opal. White Opal can range from transluscent to opaque, and colors range from white to yellow, with the most typical stones being a cream like color somewhere in between the two. White Opals are abundant and inexpensive, but are still a unique enough gemstone to act as the centerpiece to a great piece of jewelry. Opals that are share characteristics with White Opal but are transparent or more translucent are known as Crystal Opals.
Moss Opal, which can also be called Dendritic Opal, has patterns that resemble trees or plants on the face of the gemstone. They are usually range from white or cream colored to a darker brown, and fall under the broader category of Common Opal due to the lack of color play that Opals are generally renowned for.
A Summary of Opal Gemstones
In general, it is important to keep a couple of things in mind when buying/dealing with Opals. Firstly, due to their relative softness compared to some other popular gemstones, Opals should be treated with care, and should be ideally included in earrings, or pendants rather than rings and bracelets, where they have a greater chance of being chipped or broken. Also, Opals have high water content and as such should be kept away from heat and prolonged exposure to sun – these can make the stones dry up and eventually crack.
In addition to the major forms of Opal we’ve covered above, there are a huge variety of Opals that exist on the market. To learn more about some of these other varieties, you can check out Minerals.net, which is a great source for information about gemstones and minerals of all types.