What is Opal and What Class of Mineral Does it Belong To? - Stunning Blue

What is Opal and What Class of Mineral Does it Belong To?

Have you ever seen an opal in person? It’s a stunning gemstone, often referred to as “the queen of gems” due to its unique play of colors that can range from blues and greens to oranges and reds.

But what is opal and what class of mineral does it belong to? Let’s explore the answers to these questions and more.

What is Opal?

Opal is a hydrated amorphous form of silica—or silicon dioxide (SiO2). It has a hardness rating of 5.5 – 6.5 on the Mohs scale. Opals are composed of tiny spheres of amorphous silica which diffract light, creating unique patterns that vary depending on where they were formed, making each stone unique.

What are the different types of opals – black, white, boulder, crystal

Opals are fascinating gemstones known for their unique play-of-color. But did you know that there are different types of opals? The most common types include black, white, boulder, and crystal opals.

Black opals are generally considered the rarest and most valuable type, with a dark body tone that allows for vibrant colors to shine through.

White opals, on the other hand, have a lighter body tone and a more subdued play-of-color. Boulder opals are found in and amongst ironstone, which creates a striking contrast between the opal and its host rock.

Lastly, crystal opals are prized for their clarity and transparency, with a stunning play-of-color that rivals even the most vibrant black opals. Regardless of the type, each opal is uniquely beautiful and holds a special place in the world of gemstones.

Is opal a gem or stone?

Opal is a stunning mineral that has captured the attention of many people over the years. It’s unique play of colors and iridescence is unlike any other gemstone or stone. However, the question remains: is it a gem or a stone?

Opal is actually classified as a mineraloid, not a true mineral. This is because it doesn’t have a crystalline structure like other gems such as diamonds or rubies. Despite this classification, opal is still highly valued for its rarity and beauty. Whether you choose to call it a gem or stone, there’s no denying the enchanting allure of opal.

What is so special about opal?

Opal is unlike any other gemstone with its unique play of colors. It is a captivating gem with a remarkable ability to reflect the hues of the rainbow with every move. Opal is formed over millions of years by the combination of silica and water deep within the earth, resulting in its distinct composition and shimmer.

What sets opal apart is that it displays a wide range of colors that are rarely found in other stones. The beauty of this gemstone is that it is forever changing and offers a new perspective with every glance.

The rarity and complexity of opal make it a valuable and highly sought-after addition to any collection. Its beauty remains a mystery to many, but once you set your eyes on a piece of opal, you will be struck by its charm.

What is opal made of?

Opal is a precious gemstone that has captured the hearts of many. But have you ever wondered what this stunning stone is made of? Well, prepare to be dazzled because opal is quite unique.

Unlike other gemstones that are made of minerals, opal is made of hydrated amorphous silica. This means that opal doesn’t have a defined crystalline structure but instead has a random arrangement of atoms.

The result is a beautiful display of iridescence, which is why opal glimmers and shines in different colors when it catches the light. So next time you admire an opal, take a moment to appreciate its unconventional and breathtaking composition.

What Classification is Opal?

Opal is not a mineral but rather a mineraloid. A mineraloid is an amorphous substance that forms in geological settings similar to those of minerals. The main difference between opal and minerals is that minerals are crystalline solids while opal does not have an ordered arrangement of atoms. Rather, opal consists mainly of hydrated silica and water.

Opals can also be classified as either common or precious opals. Common opals have a milky white color while precious opals are composed of tiny spheres which create a “play-of-color” effect under light, resulting in brilliant flashes of color that appear when the stone is moved or tilted. This type of opal is very rare and highly sought after for jewelry making.

Is Opal Expensive?

The cost of an opal depends largely on its color, size, shape, clarity, origin, and quality. Generally speaking, common opals tend to be less expensive than precious opals but both can range from very affordable to incredibly expensive depending on the aforementioned factors. Prices can range anywhere from $10 USD for a small piece up to thousands if not $10,000+ USD for larger pieces with exquisite coloring or uncommon shapes.

The price range for opals can vary depending on their origin, color, size, clarity, and carat weight (the unit used to measure gems). Generally speaking, white opals tend to cost less than black or boulder opals due to their more common availability. Similarly, fire opals are usually less expensive than precious opals because they lack the play-of-color found in precious stones. On average, you can expect to pay anywhere from $2-$150 per carat weight for most types of opals; however prices can go as high as $1,000+ per carat weight for rarer varieties.

Why is opal only found in Australia?

The stunning beauty of opal is truly unlike any other gemstone. But did you know that this precious stone can only be found in one place on Earth? The answer is Australia.

For centuries, people have ventured deep into the Australian outback in search of these elusive gemstones. The reason for their scarcity is due to a combination of factors, including the unique geological conditions required for opal formation. Australia’s harsh environment, with its extremes of heat and drought, has helped create the perfect conditions for opal to form.

The result is a gemstone that’s not just breathtakingly beautiful, but also uniquely Australian in origin.


Opal is one gemstone that truly stands out among others thanks to its fascinating play-of-color effect that varies greatly depending on where it was formed and how it was polished afterward. While there are two main types – common and precious – both come with their own unique appeal that make them desirable additions to any collection!

Whether you’re looking for something affordable or luxurious, there’s sure to be an opal out there just perfect for you – no matter your budget! So if you’ve been wondering about this mesmerizing stone lately, now you know all about what it is and why it’s so special!

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