This gemstone holds a special place in the world of jewelry, thanks to its distinctive beauty and intriguing origins!
Let's delve into every aspect of opal; from its formation to its types, and even how to care for it.
Whether you're new to the world of gemstones or just curious about this captivating stone, you'll find all the information you need here.
Table of Contents
- What is Opal?
- How is Opal Formed?
- Types of Opal Gemstones
- Where is Opal Most Commonly Found?
- Can Opals Be Worn Every Day?
- Fascinating Facts About Opal
- How to Care for Your Opal Jewelry
1. What is Opal Gemstone?
Opal is a hydrated amorphous form of silica, which means it's made up of tiny spheres of silica that stack in a grid-like pattern, that allows light to diffract within the stone, creating a rainbow-like play of colors, known as "opalescence."
Unlike more crystalline gemstones like diamonds or sapphires, opal is classified as a mineraloid due to its lack of a definitive crystalline structure.
Think of opal as a kaleidoscope; the colors shift and change depending on how the light hits it, making each piece of opal truly one-of-a-kind!
2. How is Opal Gemstone Formed?
- Silica-rich water seeps into cracks in rocks.
- Water evaporates, leaving behind silica deposits.
- Over millions of years, these deposits accumulate and harden into opal.
The process is similar to the way stalactites form in caves but on a microscopic scale. The water content in opal can vary, typically ranging from 3% to 21%, which is why opals are often considered delicate stones.
It takes approximately 5 million years for just one centimeter of opal to form, proving nature's slow and steady craftsmanship.
3. Types of Opal Gemstones
Opal comes in several varieties, each with its unique characteristics. Here are the most common types:
1. Black Opal: With a dark body tone that makes its vibrant colors pop, black opal is considered the rarest and most valuable type, that is primarily explored in Lightning Ridge, Australia.
2. White Opal: Also known as "milky opal," this type has a light body tone with soft, pastel colors, usually found in South Australia.
3. Fire Opal: Known for its warm, fiery hues of yellow, orange, and red, fire opal is mostly found in Mexico. Unlike other types of opal gemstones, fire opal may not always display opalescence.
4. Boulder Opal: This type of opal gemstone, usually discovered in Queensland, Australia, forms within cracks of ironstone boulders, resulting in a stone that includes both opal and the surrounding rock.
5. Crystal Opal: Almost transparent, crystal opal showcases a brilliant play of colors that can be seen throughout the entire stone. It's highly prized for its clarity and vibrant color displays.
Approximately 95% of the world's opal supply comes from Australia, making it the leading source for this precious gemstone.
4. Where is Opal Most Commonly Found?
Opal deposits are found in multifarious parts of the world, however Australia is by far the largest producer. The towns of Coober Pedy, Lightning Ridge, and Andamooka in Australia are famous for their opal mines. Other opal gemstone discovery locations include Ethiopia, Mexico, Brazil, and the United States, particularly in Nevada and Idaho.
Coober Pedy is often referred to as the "opal capital of the world," where the majority of the town's population is involved in opal mining.
Source: Opal Auctions
5. Can Opals Be Worn Every Day?
Opals are absolutely stunning! However, with a rating of 5.5 to 6.5 on the Mohs scale of hardness, they are relatively soft. This means they can be scratched or damaged more easily than harder gemstones like diamonds or sapphires.
This doesn’t mean you can’t flaunt your opal gemstone jewelry on a daily basis. With proper care (tips & tricks mentioned below), opal jewelry can certainly be worn every day and last for a very long period of time. It’s essential to avoid activities that may expose the stone to rough wear and to store opal jewelry separately to prevent scratching.
Jewelry Tip: Consider setting opals in protective settings, like bezel settings, to shield the stone from potential damage.
6. Fascinating Facts About Opal
- October Birthstone: Opal is the birthstone for October, symbolizing hope, purity, and truth. It's also traditionally given for the 14th wedding anniversary.
- Opal Superstitions: In the Middle Ages, opal gemstones were believed to bring good luck because they contained the colors of all other gemstones. However, in later centuries, they were thought to be unlucky, especially for those not born in October.
- Unique Patterns: Each opal is unique, with patterns like harlequin, pinfire, and rolling flash. These patterns determine the value and appeal of the gemstone.
Source: Altmann + Cherny
A rare black opal called "Aurora Australis" was discovered in 1938 at Lightning Ridge and is valued at over $1 million.
7. How to Care for Your Opal Jewelry
To keep your opal jewelry looking its best, follow these care tips:
- Avoid Water: Although opals contain water, prolonged exposure to liquids can cause "crazing," where the stone develops tiny cracks.
- Clean Gently: Use a soft cloth to clean your opal jewelry. Avoid harsh chemicals or ultrasonic cleaners, which can damage the stone.
- Store Safely: Store opals in a soft, padded cloth or box. Consider keeping them in a slightly humid environment to prevent them from drying out.
If your opal develops cracks, take it to a jeweler for professional assessment and possible repair.
With that, we’ve come to an end…
Opal is a gemstone that embodies both beauty and mystery. Whether you're drawn to its stunning play of colors or its rich history, opal is a gem worth exploring (figuratively speaking!).
By understanding how it's formed, where it comes from, and how to care for it, you can truly appreciate this unique gemstone.