Boulder Opal ✨ Meaning ✦ Properties ✦ Benefits ✦ Uses

Boulder Opal History

This gemstone was first discovered in 1869 in Blackall town in central Queensland, Australia. while there were several discoveries in the 1870s, boulder opal was only introduced to the European market in the 1890s. Its normally mined from huge ironstone boulders and they form in fissures and cracks of these boulders. Over the years, boulder opals have gained a great reputation and their value is undisputed in the gem industry.

Boulder Opal patterns
Formula (repeating unit)Hydrated silica. SiO2·nH2O
Crystal systemAmorphous
Crystal habitIrregular veins, in masses, in nodules
FractureConchoidal to uneven
Mohs scale hardness5.5 – 6
LusterSubvitreous to waxy
Diaphaneityopaque, translucent, transparent
Specific gravity2.15+0.08
Density2.09 g/cm3
Polish lusterVitreous to resinous
Optical propertiesSingle refractive, often anomalous double refractive due to strain
Refractive index1.450+0.020
Absorption spectragreen stones: 660 nm, 470 nm cutoff
Diagnostic featuresdarkening upon heating
Solubilityhot saltwater, bases, methanol, humic acid, hydrofluoric acid

Where is Boulder Stone Found

This well-documented stone is primarily found in Queensland, Australia. However, it can also be found in other parts of the world including Brazil, Canada, and New South Wales. In Queensland, this stone is found in Quippier and Winton which are areas that have large opal fields.

Boulder Opal

Boulder Stone Colors

This gemstone displays an array of bright and vibrant colors. But due to the dark backing of the ironstone, then this stone tends to have a darker body tone and this usually leads to a vibrancy of various colors that resemble those colors found in black opals.


The type of colors seen depends on the regularity of the internal spheres and how they are packed. Besides that, the size of the spheres, as well as the voids between them, are critical in influencing the color spectrum. Once you move the stone around and a different source of lighting hits the spheres, then the perceived color change will depend on the angles that the light source hits the sphere.

Video source: YouTube / Opals Down Under

Note that if the ironstones that are responsible for the dark body tone can be seen on the surface of boulder opal, then the stone will end up having a motley or spotted appearance. In this case, its value will reduce. The most priced boulder opals usually have a clean face that makes the whole color bar visible.

Boulder Opal Patterns

In terms of pattern, Boulder Opals have some close resemblance to Black Opals. It has patterns such as ribbon, Chinese writing, harlequin, floral, straw, and rolling flash among others.

Boulder Opal Varieties

The typical type of Boulder Opal is the Queensland Boulder Opal that’s usually mined in the vast Opal fields found in Queensland.

Video source: YouTube / Liz Kreate

One thing that you will notice about this Australian is that it has striking red ironstone that’s found within the stone. But even within this realm, you will find that there are various types of gemstones and they include:

1. Yowah Nuts

This variety of boulder opal is only found in the Yowah area of Queensland. From its name, Yowah Nuts usually have the natural shape of nuts. The Yowah area is known to produce large quantities of this boulder opal variety but, unfortunately, most of these gemstones don’t have color. They simply appear in the form of brown ironstone without distinct colors or stone patterns.

2. Koroit Opal

It derives its name from the Koroit Opal fields in Queensland. This distinctive boulder opal variety has a unique appearance that has made it popular in the jewelry world. it has pure ironstone just like the main stone even though it bears some resemblance to the Matrix Opal.

3. Matrix Opal

This variety has an intimate diffusion of infillings found in the holes or pores between its grains. Its primarily found in the Queensland area and it can be effectively distinguished from the host rock. It’s generally described as the matrix of ironstone and other types of stones in addition to Precious Opal. Besides that, it could also be a matrix of ironstone, sandstone, and clay.

The common types of Matrix Opal variety include the Solid Matrix Opal, Concrete Matrix Opal, Sandstone Matrix Opal, and the Honduran Matrix Opal. Generally, the Solid Matrix Opal is more expensive compared to Concrete Matrix Opal.

4. Tintenbar Opal

It got its name from its geographical area of North Eastern NSW. Note that this area encompasses several opal fields as well as discovery areas. It’s also the only area that’s known to produce large quantities of precious opal for commercial use hence it’s also known as the volcanic geological environment. However, this type of opal isn’t usually stable even though it comes with attractive deep dark hues and perfectly makes great doublets.

5. Mintabie Opal

Mintabie is another open mining area in South Australia. This region has gained notoriety for producing opals with great crystals. additionally, opals from Mintabie have unique fire and color contrasts and this makes them ideal in providing attractive triplets.

6. Fairy Opal

This is simply a natural opal that has been treated. Note that Boulder Opal is a natural gemstone while Boulder Fairy Opal is a type of cooked sandstone opal that has undergone treatment.

Boulder Opal Clarity and Cut

The clarity of a gemstone refers to how well we can see through its body and if there’s a presence of blemishes or flaws inside. High-quality gemstones are usually transparent and this means that it’s possible to see through it and see things from the other end. But there are also translucent gemstones that allow light to shine through even though we can’t see the images or shapes within. Lastly, there are opaque gemstones that block all forms of light.

Video source: YouTube / Christian Leon Watts

Well, when a boulder opal is still connected to solid rock, it will be completely opaque as no light can pass through the ironstone. However, the treatment of the opal material should, however, result in a gemstone with a transparent surface. As a result, you should be able to see through the mesmerizing array of color play.

When it comes to cuts, Boulder Opal gemstones are never faceted and so they are usually cut into cabochons. It should be noted that the cabochons cuts can be found in cure interesting shapes as well as odd shapes. The goal is to ensure that the best patterns and colors of the stone are captured.

Spiritual Meaning of Boulder Opal

What makes Boulder Opal a precious stone with spiritual meaning is its vibrant and bright colors. This natural ironstone also comes in quite interesting shapes that may have their unique meanings. The brilliant “Play of Fire” color usually flashes different hues and tones depending on the surrounding lighting conditions.

Spiritually, this gem is said to be effective in calming the inner soul. It works by perfectly representing the existing interplay of various emotional elements as viewed by its refracting colors. It’s effective in facilitating self-awareness and the process of personal actualization.

The stone can be used to connect different parts of the conscious mind and the subconscious. This link, consequentially, helps to promote a clearer understanding of self.

Its effectiveness is enhanced by the fact that it can also facilitate the communication between the Mystic Realm and the Earth Plane. In some instances, Boulder Opal is used to aiding the connection or find the meaning of hidden information displayed in dreams or to quest a vision. The spiritual aspect of this natural stone is quite diverse but using it can brighten and clear your aura, leading to emotional and spiritual healing.

Boulder Opal and Chakras

The frequency of this natural stone means that it can effectively connect to the base as well as the crown of chakras. It perfectly integrates with higher vibrations that emerge from your soul, allowing you to “see” and “know” the “bigger picture” that’s related to your life. This way, you can live your life to the fullest as you should and this is infused with your personality.

The 7 chakras and their color relations include:

  • Crown: purple
  • Third eye: indigo
  • Throat: blue
  • Heart: green
  • Sacral: orange
  • Solar plexus: yellow
  • Root: red

Boulder Opals come in a wide range of colors and this makes them ideal for use with chakras. Besides that, the energy frequency they possess has led people to associate them with the Crown and Root Chakras even though the other colors still have influence.

When your chakras are blocked, you end up experiencing various physical and emotional issues and they, therefore, need to be cleansed for you to reach your higher self. And one of the most effective ways to carry out the cleansing process is by using crystals and gemstones such as Boulder Opals.

Boulder Opal and Zodiac

This gem is considered to be the official birthstone of October. Besides that, it’s also the Zodiac stone for Scorpio, Pisces, Libra, and Cancer. Sometimes this astrological gemstone is used as the Virgo sign.

So, if your loved one celebrates their birthday in October or November, then you can buy them this stone since it’s their birthstone. Besides that, those with the aforementioned Zodiac signs can use them when they have troubles in life in the hopes of getting a better future. It perfectly suits all the water signs since its composition features a high amount of water.

For instance, Scorpios, Cancers, and Pisces can use this gem to build a strong faith and channel their energies to accomplishing whatever they have imagined. This is an essential feature since these Zodiac signs usually lack consistency and determination in their daily activities that lead to productivity.

It’s also worth noting that this stone also serves as a soul purifier and can be a great indicator of a joyous life. Overall, it helps those with water signs in Zodiac to attract positive energies and inspire them to move towards satisfaction. For effectiveness, you can wear it as part of your jewelry i.e., earrings, necklace, ring, or pendant.

Are Boulder Opal Birthstones?

Yes, Boulder Opals are the official October birthstones. This was adopted in 1912 by the American National Association of Jewelers. Besides that, this gemstone is also the official birthstone of the Libra zodiac sign.

Boulder Opal Price

Boulder Opal is quite expensive due to the intensity of the mystical fire found inside it. That’s has significantly popularized it. However, the price of opal isn’t usually based on carat measurements. This is because of the large ironstone that’s usually found in it.

Video source: YouTube / Quest TV

But rough estimates indicate that a premium boulder opal can cost between $2 and $15 per carat for a multicolor boulder opal. Meanwhile, a strong multicolor stone can fetch as high as $800 per carat.

Video source: YouTube / Pulitzer Opal

Health Benefits of Boulder Opal

Boulder Opals have healing properties. They are normally used as an alternative form of treatment to promote wellness. In the traditional setting, opal has always been associated with promoting good eye health. It’s capable of soothing the eye and that’s why there are products such as the opal elixir eyes wash that can be used to treat sore eyes.

Besides that, this gemstone can be used to regulate the levels of insulin in the body as well as promote the regeneration and detoxification of the liver. This makes the stone ideal in minimizing the chances of inflammatory conditions and facilitate the elimination of damaging radicals that lead to the development of fine lines and wrinkles.

Since boulder opals are known to be the official birthstones of October, it’s clear that they can also help with childbirth. You can wear it as a source of good luck during delivery with the hope of getting a healthy child. Women can also wear it to manage the harsh side effects of PMS and menopause since its effectiveness in promoting a feeling of calmness and promoting relaxation of the mind and the body.

If you are struggling with lymph nodes and bladder issues, boulder opals can also be ideal for use in such cases. The fact that they help promote the efficient movement of wastes outside the kidneys and ensure that your body is well-nourished is something that you should try out.

If you are struggling with abdominal pain, lower backaches, and muscle tension, using this gem can come in handy. Alternatively, those struggling with disorders such as Parkinson’s disease can use these gemstones to boost memory function and stimulate the efficient operation of nerve endings in detecting pain.

If you are struggling with panic attacks, anxiety, or even phobias, then this gemstone can come in handy. Overall, boulder opals have proven to be effective in helping people manage both emotional and physical issues without resulting in harsh side effects.

Emoche ✦ The Crystal Authority