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Opal Engagement Ring – Your Ultimate Buying Guide

Opal engagement ring

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Known for its unique appearance, opal has been a popular gemstone used in jewelry for centuries. As October’s birthstone and the official gemstone for the 14th wedding anniversary, opal is a highly sought after stone.

Opal is a beautiful gemstone that’s commonly used in various types of jewelry, but does it mean that it’s suitable for an engagement ring? In this article, we’ll be taking a closer look at this distinctive gemstone and whether it’s the right choice for your engagement ring. We’ve also included some stunning opal engagement ring designs.

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What is an Opal?

Opal gemstone

Opals are beautiful gemstones composed of minuscule silica spheres in a hydrated form.  It contains about 3 to 10% of water. If the silica spheres in an opal are uniform in shape and size, the stone will display the play of color which is what makes it so unique. Some say that the colors look like lightning, galaxies or fireworks trapped within the stone.

The name ‘opal’ is said to have derived from the Sanskrit upala which means ‘precious stone’ or ‘jewel’ and later on the Greek word ‘opallios’ meaning ‘to see a change of color’.

Opals are formed when rainwater seeps into and evaporates in fissures of various rocks, the most common being sandstone, marl, basalt, limonite and rhyolite. It leaves behind the silica deposits which create the stunning colors of the stone. It’s found in all parts of the world including Mexico, USA, Ethiopia and Indonesia, but Australia produces over 90% of the world’s precious opals.

Although opals aren’t very hard gemstones, they’ve become extremely popular for jewelry over the years. They’re also very popular for engagement rings because of their beauty and rich look.

Types of Opal

If you’re considering an opal for your engagement ring, you’ll need to know the different types of this gemstone. These types are divided into two categories: ‘precious’ and ‘common’. While precious opals are highly priced and used for jewelry, common opals are used for various other purposes since they’re far too soft.

Precious Opals

Let’s start by taking a look at various types of precious opals available on the market.

Black Opals

Australian black opal ring

Australian black opal engagement ring by Anderson Beattie. See it here.

These are the rarest of all opals and the most highly valued. Black opals have a dark body tone against which they display all the colors of the spectrum. The contrast of the colors against the black background gives the stone a gorgeous, rich look.

Crystal Opals

Crystal gold signet ring

Crystal opal gold signet ring by NIXIN Jewelry. See it here.

These are translucent stones that allow light to pass through them when illuminated. It was named ‘crystal opal’ because of its translucency which makes it look like crystalline materials. However, crystal opals aren’t actually crystalline in structure.

White Opals

White opal engagement ring

White opal engagement ring by K Best Design. See it here.

Also called ‘milky opal’, these stones have a pastel-like appearance and a light body tone. They display any color of the spectrum in a stunning play of color.

Boulder Opals

Boulder opal

Australian boulder opal ring by Sacred And Coveted. See it here.

Formed in sandstone or ironstone, boulder opals come connected to their host rocks.  It’s different from the other precious opals because it’s slightly harder and far more stable.

Common Opals

Also called ‘potch’, common opals are opals that don’t display any play-of-color or iridescence that’s typically seen in precious opals. While the two types are made from the same mineral, the silica spheres in potch are all different sizes and mixed up, whereas in precious opals they’re all uniform and neatly aligned.

Since potch is too soft to be used in jewelry, it’s used as fillers, insulation media and abrasives. It’s also an important ingredient in the making of ceramics.

Evaluating an Opal Gemstone

Like all other gemstones, the value of an opal can be evaluated in terms of cut, color, clarity and carat (also known as the 4Cs), but there are also several other quality factors. If you’re interested in buying an opal engagement ring, you’ll need to take these factors into consideration:


Opal cutting is a very difficult task that can produce unusual outcomes. These stones are typically cut in a way so that the stone will be as large as possible so as to minimize waste. While the shape is decided according to the size and shape of the stone, opals are cut into ovals and cabochon-shaped which is a dome shape.

However, most opal stones are cut into freeform shapes which depend on the deposition of the opal and the flaws inside it. There are also opals cut into various other shapes including teardrops, rectangles, triangles and squares.

Play of Color

When choosing an opal gemstone, look for one with an intense play of color that’s evenly distributed across the stone. The harlequin play of color pattern consists of equal-sized mosaic patches (similar to patchwork) and is considered as the most desirable.  In white opals, the play of color pattern is more like a series of colorful, bright dots.

If the color red can be seen in any opal, the stone will be highly valued. Therefore, take a good look at the stone for a fiery, red look all over it.

Never buy an opal that looks cloudy since this can signify that the gemstone is too dry and can crack at any minute. Sometimes merchants sell opals placed in jars of water if the stones have a high water content. However, these stones are prone to cracking, so avoid buying them.


While all opals will have some flaws or inclusions that can’t be seen by the naked eye, you’ll also come across those with crazing (tiny cracks) or other imperfections on the surface. These flaws can reduce the value of the stone, especially if they’re visible to the naked eye.

Sometimes, bits of rock or sand can be embedded inside the opal so if you notice flaws like these, you might want to avoid buying the stone. Poor clarity will not only affect the stone’s beauty but it will also decrease its overall value.


Most gemstones are valued according to their carat weight, however this is not the case with opals. The value of an opal doesn’t increase with its size.

The weight of opals is measured in carats with one carat equal to 0.2 grams. Opals that are any bigger than 2-10 carats (from 0.4 to 2.0 grams) are still highly prized, but they’re less viable for jewelry which means the value (or carat) can decrease.

Opal Engagement Ring Settings and Styles

The opal is a fairly soft stone, ranking at 5.5 – 6.5 on Mohs’ scale of hardness. If you’re planning on having an opal engagement ring, you’ll need to find a style and setting that will protect the stone while highlighting its beauty.

Here are some stunning engagement ring designs with different settings featuring this beautiful gemstone.

Prong Setting

Natural opal engagement ring

Opal engagement ring with prong setting by Brilliant Forever. See it here.

The prong setting is commonly used for opal engagement rings since it allows the gemstone to be visible from the sides. High-domed cabochons are typically set in prong settings but there are also opals in various other shapes with fewer or more prongs.

While the prong setting is classy and elegant, it’s not very secure since the stone can loosen and fall out over time. An opal set in prongs can easily be knocked and damaged since so much of it is exposed.

Bezel Setting

Bezel set opal ring

Bezel set opal engagement ring by L Studio C. See it here.

Bezel settings provide more protection for the gemstone than prong settings since they wrap around the sides of the entire stone. The bezel setting is perfect for flatter opals and has a nice rustic or bohemian look to them.  

Open-Back Setting

Engagement rings with open-back settings are perfect for solid opals and have a unique look but they do come with a few disadvantages. The opal will be exposed not only from the front but from the back as well which means it could easily get damaged. If the gemstone protrudes from the back or if it’s slightly uneven, you won’t find it very comfortable to wear.

Closed-Back Setting

While closed-back settings are much safer than open-backed settings, they can affect the color of the opal. It’s important to choose the right type and color of setting so that the beauty of the stone won’t be diminished.

An opal set in a closed white gold or silver setting can display a cooler tone and look washed out. However, when set in a closed yellow gold or rose gold setting, it can have a warmer tone. In this case, an opal that already has a warm tone can look even more yellow than it actually is. Yellow opals are highly valued so you might want to carefully consider the color of the closed back setting.

Opal Symbolism

In the past, especially during the Middle Ages, opals were strongly associated with good luck and royalty. The Romans viewed this gemstone as a symbol of hope and believed that it would always bring them good fortune.

Over time, however, this lovely gemstone became an object of many negative superstitions to the point where some people believe that it brings bad luck. In fact, black opals are considered the only type of opals to be unlucky whereas all the others are associated with misfortune.

The negative beliefs stemmed from the story of the Spanish King Alfonzo who gifted his wife with a beautiful opal ring. She soon died and the ring was passed on to the rest of his family members who all died one by one, shortly after receiving it. Finally, it found its way back to Alfonzo who decided to wear it without fear but he too met the same fate as his family members.

It’s possible that the deaths of King Alfonzo and his family could have been due to old age or diseases like typhoid fever or the deadly Cholera epidemic that had claimed many lives. However, the connection between opal gemstones and death continued to grow stronger.

Today, it’s believed that only those born in October can wear the opal since it’s the official birthstone of the month. If anyone else wears it, they’ll be inviting bad luck into their life.  

Synthetic (or ‘Fake) Opals

Synthetic opals aren’t entirely fake since they contain the same properties as real opals. To make synthetic opals, a certain amount of real opal is mixed with other materials. Since most of the opals sold today are synthetic stones, knowing how to identify them will be useful when you go shopping for your own opal.

The main difference between synthetic and real opals is their density. Real opals are far more dense than synthetic stones and when viewed under a magnifying glass, you won’t see any regularity in their color. Synthetic opals, on the other hand, have a regular pattern of color and are much lighter than the real thing.

Illuminating an opal with UV light is another easy way to check if it’s synthetic or real. If the stone shines or glows brightly, it’s most likely a real opal. Synthetic opals don’t have a naturally bright shine.

Opal Doublets and Triplets

Australian opal doublet ring

Australian opal doublet ring by 27th Ave Designs. See it here.

Opal doublets are created by attaching a thin slice of solid, precious opal to a backing that’s darker in color. As a result, it looks like solid black opal. Doublets aren’t as valuable as solid opals but they’re an excellent choice if solid opals are beyond your budget.

Opal triplets are made in the same way as doublets, by sticking very thin slices of precious opal between a dark backing and a slice of quartz or glass. Triplets are a lot less expensive than doublets but they can get a faded, foggy look over time because of the glue used to hold them together.

How to Take Care of an Opal Engagement Ring

Since opals aren’t highly durable gemstones, they do require quite a bit of extra care. However, they’re often worth the extra effort because if cared for properly, they can last you a lifetime. Here are some tips on how to take care of your opal engagement ring the right way.

  • Wash with mild detergent and warm water. When washing your opal engagement ring, avoid using strong detergents and never scrub the piece since this can cause scratches on the surface, making it look dull.
  • Avoid exposing the piece to extreme temperatures. Opals generally have a very high water content which means they can crack when exposed to extreme temperature changes. Don’t expose your opal ring to heat or dryness for prolonged periods of time since this can cause the stone to develop fractures all over its surface.
  • Avoid using ultrasonic cleaners. Opals are too delicate for ultrasonic cleaners and can crack due to the vibrations.
  • Never expose the piece to harsh chemicals. Keep your opal engagement ring well away from all harsh chemicals like bleach, chlorine or even cosmetics and lotions.
  • Don’t wear your ring when swimming. The chlorine in water can damage your opal gemstone or what’s worse: you might lose it in the water.
  • Take off your opal engagement ring when engaging in rough activities. If you’re an outdoorsy person who enjoys rock climbing, gardening or any other type of physical activity, remember to remove your ring first. Opals can easily crack if dealt a hard blow.
  • Don’t soak your opal ring for prolonged periods of time. Water can spoil doublets or triplets by damaging the glue holding them together and some opals can absorb water along with its contaminants.

Where and How to Buy Opal Engagement Rings

Since opals are quite difficult evaluate, many jewelers tend to pass off low quality stones for high prices. To avoid getting scammed, purchase your opal from a reputable vendor with an impressive track record.

Not only will the vendor answer any questions you may have, they should also give you all the information you need to know about your opal. In most cases, you will receive a certificate of authenticity.

If you’re looking to purchase online, you will find many opal collections on jewelry sites that offer birthstone jewelry. We recommend searching on Blue Nile, as well as Amazon and Etsy.

  • Etsy offers a wide range of synthetic and solid opal engagement rings, at various prices. They also have loose opals, if you’re looking to purchase just the stone.
  • Amazon is one of the largest online retailers in the world. They offer an extensive range of opal engagement rings in all shapes and sizes.

Before your purchase your opal engagement ring or gemstone, make sure to check out the vendor’s policies and rules. You might have to do a little bit of digging but it’ll be worth it when you find the perfect opal piece for you. Gauge the quality of the product by checking the seller’s ratings and going through the review sections which will give you a good idea of what you’re buying.