Boulder Opals: History, Symbolism, Meanings, and More!

boulder opal gemstonesIf you ran a kingdom like the Roman Empire, what would it take for you to share it with someone else? Legend has it that for a Roman emperor, one opal was enough for him to consider trading one-third of his entire kingdom. Unfortunately, that legend doesn’t indicate which emperor, but we know for a fact that many Romans coveted opals. 

Just look at Mark Antony — he may have preached about morals and what it means to be an honorable man, but we’re talking about a guy that banished a senator for refusing to sell him an opal! Talk about spoiled! Love makes you do crazy things, and we know that Antony collected this October birthstone for his lover, Cleopatra. The stone was worth 2,000,000 sesterces, or $80,000 in today’s dollars. 

So why have opals been the talk of the town since Ancient Rome? Many reasons, but their gorgeous rainbow tones and vivid colors come to mind first. 

Today we’ll cover one special type of opal: the Australian boulder opal. Where is boulder opal found? Almost exclusively in Queensland, Australia. 

You might be wondering, “what is boulder opal?” We’ll answer that, along with the boulder opal metaphysical properties, price, jewelry, and everything else you need to know about boulder opals. 

First, let’s touch upon the boulder opal meaning. 

boulder opal carving flower

What Does Boulder Opal Represent?

We know that opals generally symbolize innocence, hope, and purity. 

Boulder opals have a more specific meaning. These one-of-a-kind gemstones symbolize serenity, specifically of the soul. Their bending colors reflect the chaotic and mixed emotions we carry as humans. 

Opal is derived from the Greek word opallios, which means “seeing a change of color.” That Greek word modifies the ancient Indian Sanskrit upala, meaning “precious stone.”

So what does boulder opal mean spiritually? 

Carrying all these colors in one, boulder opals link your conscious and subconscious, representing clear communication, clarity, and understanding.  In Ancient Egypt, Rome, and Greece, opals were symbols of hope, purity, healing, and prophecy (or foresight.) 

Tell me more about those bending colors! What do boulder opals look like?


Boulder Opal Physical Properties

Found only in Western Queensland, Australia, boulder opals are quite rare.  They display the wonderful colors of other opals but are mixed with ironstone, making them more durable. 

But what is the difference between opal and boulder opal? 

They’re pretty similar in their physical properties, including shape and color. The main difference is boulder opals have a layer of solid ironstone on their backs. And, because they’re mixed with ironstone, they are more durable. Plus, the ironstone makes the color of boulder opals even more iridescent and beautiful. 

So, how is boulder opal formed?

Boulder opals formed millions of years ago. They occur as thin veins of opal in the cracks of rocks after they’ve mixed with water. When the water seeps into the cracks, ironstone forms. When cut, the natural ironstone remains as the backing, and the opal is then mixed with ironstone, displaying flashing flecks of color throughout. 

yowah nut boulder opal

Boulder Opal Color

Throughout boulder opal’s formation, hydrated silicon dioxide and water mix with the amorphous structure of the stone to create tiny spheres. When light passes through, it interacts with different spheres and angles within the stone, constantly changing the colors of boulder opals. 

You might see cool tones of blue and green, but also fiery colors like red or orange; it all depends on the light. These divine colors led Ancient Greeks to believe that opals were tears of the thunder god, Zeus!

All opals have the enchanting ability to shift colors as light passes through the stones, and boulder opals are no exception. The ironstone actually enhances the boulder opal’s play of color and opalescence

Something particularly fascinating about boulder opals is that they sometimes show circular veins of vegetation, specifically plants or trees. 

Is boulder opal petrified wood? It might seem that way, but the stone still originates from ironstone, not wood. Known also as fossil wood replacement opals, these particular boulder opals are quite rare. 

How about the shape? 

yowah nut boulder opal cabochon

Boulder Opal Cabochon

These stones are never faceted; instead, they’re cut into cabochons, a style of cutting with the purpose of best displaying the various colors of the boulder opal. 

Gemstone cutters (lapidarists) shape and polish, not facet, cabochon cuts, giving them convex faces and a dome-shaped base. Their round shape (no corners or edges) makes them more resistant to breakage or scratching. This is especially beneficial for opals, as they rank only a 6 on the Mohs hardness scale

boulder opal pendant

Boulder Opal Healing Properties

Are boulder opals all about beauty? Surprisingly no, though their beauty dazzles us! 

Associated with the Crown and Root chakra, boulder opals also have impressive physical and emotional healing properties. The Crown chakra connects your mental self to your spirit. A balanced crown chakra facilitates self-knowledge, unity, and universal consciousness. It’s only fitting that the boulder opal is known to connect your conscious with your subconscious!

Your root chakra is your rock (one might even say, your boulder), as it offers you grounding and stability. A well-balanced root chakra helps you tackle each day without worry and fear, uniting with the boulder opal’s symbolism of clarity and understanding. 

What is boulder opal used for?

Physically, opals are known for promoting eye and liver health, as well as fertility health. They’re known to assist with PMS, menopause, and childbirth. Some crystal healers also use them to soothe muscle tension and enhance memory!

Emotionally, boulder opals are great calming stones for phobias, anxiety, and panic attacks. To find calm with boulder opals, we recommend holding them while meditating. 

All these health benefits must come at a price, right? So, are boulder opals valuable? Let’s take a look at the boulder opal price per carat.

boulder opal pendant

Boulder Opal Price

First thing’s first: boulder opals are not for those on a tight budget. These are some of the most expensive opals on the market. But why is boulder opal so expensive?

Firstly, boulder opals are mined in remote areas of Queensland, Australia, making for some harsh, dry mining conditions that require expensive machinery and highly skilled miners. 

Is boulder opal rare? Yes. With limited locations for mining, it’s fair to say that boulder opals are rare, contributing to their price point.

Third, the ironstone mixed with the opal produces more enhanced colors, offering boulder opals a coloring more unique than other opals. More beauty equals more demand, meaning higher prices. 

Finally, the cutting process for boulder opals is often done by hand, resulting in higher costs for labor. 

Are boulder opals valuable? Given all the above characteristics, they certainly are. The boulder opal price per carat can be up to $3,500!

Now, let's get into more detail about those mining conditions for boulder opals.

boulder opal wood fossil specimen

Boulder Opal Mining

As mentioned, almost all boulder opal mining takes place in Queensland, Australia. The first opal was discovered in 1869 on Listowel Downs in Queensland. The first boulder opal was found in Blackall,  a small town in central Queensland.

Today, boulder opals are mined above ground in sedimentary and Cretaceous rocks along Western Queensland. Popular mines include:

yowah nut boulder opal

Yowah Opal Mining Field

The Yowah mining area is well-known for a brown boulder opal called the ironstone matrix opal and the Yowah opal nut, another opal variety found only in this part of Queensland. 

For geographic reference, Yowah is mostly located halfway between Thargomindah and Cunnamulla.

What is the difference between matrix opal and boulder opal? 

Well, they’re both quite similar. You can find both matrix opals and boulder opals in Queensland, Australia, except matrix opals are only found in the Yowah opal field. The main difference between the two is that boulder opal veins are larger than matrix opal veins.

koroit boulder opal

Koroit Opal Mining Field

Not far from the Yowah mine is the Koroit Opal Mining Field. This is one of Australia’s most well-known and vibrant opal fields, producing the stunning Koroit opal.  A black boulder opal, koroit opal has the best value for money when it comes to opals. It boasts lovely inclusions of spectacular color.

Rough boulder opal from Koroit is hard to cut and split, often requiring highly skilled hands. A miner must carefully nick the inclusion, a vein of color, to evenly split the rock. Once split evenly, you can see its marvelous colors. 

boulder opal ring with diamonds

Boulder Opal Jewelry

Make a fashion statement and channel mystical wisdom and purity with a boulder opal ring or boulder opal pendant. Many covet boulder opal earrings since it's hard to find a pair of matching stones.

Ready to Rock Some Boulder Opal Jewelry?

Thinking about rocking some boulder opal earrings? With the vast array of colors within boulder opals, finding matching pairs for earrings can be difficult. Luckily, we have tons of matching boulder opal for sale to browse through today! 

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