Rock Discoveries

Unearthing the Beauty: A Guide to Different Types of Opals

Opals are a fascinating gemstone that, due to their play of colors, have captivated the hearts of admirers for centuries. Each kind of opal found around the world has unique characteristics that set it apart from the others.

In this article, we will explore the ten different kinds of opal, their defining traits, and where they can be found.

Australian Opal

Perhaps the most well-known of all the opals is the

Australian Opal. This kind of opal is favored by jewelers and collectors around the world for its vibrant hues and stable body color.

Contrary to common belief,

Australian Opals are not exclusively black. In fact, these opals come in a wide range of colors, from light pink to deep blue.

However, the most valuable of them all are those that showcase a play of color on a white body color base. The white base makes for a very stable opal that does not tend to crack or craze over time.

For this reason, it is considered a gem-grade stone and loved for its durability. This kind of opal is the most traditional and most commonly seen in classic jewelry pieces.

Australian Opals are also found in doublets or triplets which involve a thin layer of the stone affixed to a dark backing to enhance the play of color.

When it comes to pricing,

Australian Opals demand a premium price.

However, there are cheaper alternatives to obtain the striking play of color and the durability that make

Australian Opals famous.

Welo Opal

Welo Opal is unique among opals for its hydrophane trait, meaning it can absorb water. This makes

Welo Opal highly unstable, making it challenging to cut and polish, and easily subject to crazing or developing cracks.

Welo Opals have a transparency that allows you to see through it and features play of color in various hues, often with an orange tint.

Boulder Opal

Boulder Opals come sandwiched inside a matrix of ironstone or sandstone, giving them a mottled appearance. As opposed to the classic white body color that is typical of other opals, this kind of opal has a brown or bluish-grey tone with flashes of fiery hues that make it a striking piece.

The distinctiveness of the ironstone matrix increases the value of the stone, making it highly sought after by collectors and connoisseurs.

Black Opal

Black Opals are considered the rarest type of opals, found exclusively in Lightning Ridge in Australia. True to their name, they have a black or dark body tone that can be occasional or permanent.

They feature fiery flashes of color that are often more intense than other opals, making them highly prized and expensive.

Matrix Opal

Matrix Opals are found in the Australian fields and are usually interspersed with smaller particles. They are unique among other opals for the detailed patterns and intricate designs that frequently adorn the stone, making it perfect for creating unique pieces of jewelry.

Andamooka field in South Australia is known for its

Matrix Opals.

Dendritic Opal

Dendritic Opals are milky with a semi-transparent white body color. They have black dendrite inclusions made of metallic oxides, creating an appearance similar to ferns, trees, flowers, and other organic elements.

These opals often have unique, intricate patterns, and a subtle play of color, making for strikingly beautiful pieces at a lower price point.

Fire Opal

Fire Opals are uniquely found in Mexico. They are highly transparent and feature hues from white to yellow to bright orange and reds, giving it the fiery appeal that earned its name.

Fire opals, also known as jelly opals, are transparent stones known for their bright coloring and showstopping appearance.

Cantera Opal

Unique to Mexico,

Cantera Opals are found in rhyolite and are often used for carvings due to their intricate patterns and natural voids that create breathtaking designs in the stone. The delicacy of the stone makes it less common in jewelry but prized in art and sculpture creations.

Madagascar Opal

Madagascar Opals come in a fascinating olive-green color with a mottled appearance. Common opals, they are typically cheaper than other kinds of opals, making for affordable pieces of jewelry.

These stones are not as flashy as some of the other kinds of opals, but rather have a subtle, elegant beauty.

Peruvian Common Opal

Peruvian Comman Opals come in light, sky-blue color with hints of pink and blue. They tend to have dendrites in them, which create organic patterns.

Due to their stability, these opals are often used in jewelry making and are a great alternative to

Australian Opals. In conclusion, opals come in various characteristics and qualities, making them unique and fascinating to collect or wear.

Whether it’s the sought-after play of color and durability of

Australian Opal, the rarity of

Black Opal, or the intricate patterns of the

Matrix Opal. Each variety offers a unique way to add elegance and fascination to the pieces of jewelry or artwork you create.


Welo Opal

Welo Opal is a fascinating stone that hails from the Wollo Province of Ethiopia. It is unique among opals for its hydrophane trait, making it a highly unstable gemstone.

Hydrophane means that the opal can absorb water, making it prone to developing crazes or cracks quickly. For this reason,

Welo Opal requires delicate handling and care when cutting and setting into jewelry pieces.

One of the most striking features of

Welo Opal is its transparency, making it one of the few opals that allow you to see through it. This transparency allows

Welo Opal to showcase a play of color typically not seen in other opaque opals.

The colors of a

Welo Opal range from cool blues to deep greens. The flashes of fiery hues that often accompany this kind of opal carry an orange tint that is characteristic of the stone.


Welo Opals can be pricey due to their rarity and the challenges that come with extracting them, they are generally accessible and more affordable than some other opal varieties. Due to their opaqueness, gems of high transparency are rare, but large pieces of these opals boast comparatively bigger color displays than most other opals.

Welo Opals require careful cutting and polishing to enhance their beauty and raise their value. Jewelers who specialize in the cut and setting of

Welo Opals work with special equipment and techniques to avoid cracking.

As much as possible, the stone should be kept out of water to prevent damage, as

Welo Opal is highly sensitive even to humidity and temperature fluctuations. When buying

Welo Opals, it’s essential to make sure you’re purchasing them from a well-respected dealer.

Due to their instability, unethical dealers have been known to sell fake or stabilized opals to unwary buyers at exorbitant prices.


Boulder Opal

Boulder Opal is a type of opal found in Queensland, Australia, and is unique among other kinds of opals in its appearance and composition. Unlike most opals,

Boulder Opals occur as thin veins or layers of precious opal inside a brown or bluish-grey sandstone or ironstone matrix.

The combination of the precious opal and the host rock creates the stone’s mottled appearance that is often considered a freak of nature.

One of the most significant features that make

Boulder Opals distinct is the volume and quality of their precious opal.

The precious opal that forms in

Boulder Opal is relatively thick, allowing it to be cut and polished into beautiful cabochons or carvings while still retaining much of its natural beauty.

Boulder Opal can showcase myriad colors, ranging from deep blues to vibrant purples or oranges.

Due to the nature of its host rock,

Boulder Opal is not often as widely available as other opals, making it a rarity in the market. This opal is a highly specialized variety that has a unique and naturally-occurring composition that makes it a valuable addition to any collection.

Craftsmen who specialize in creating jewelry and artwork with

Boulder Opals require a particular level of expertise. Working with the stone to enhance its color and beauty requires a high degree of care and skill to avoid damaging the precious opal and emphasize its natural appearance.

In summary,

Boulder Opal is a unique type of opal that boasts an exceptional composition and appearance. The precious opal in the sandstone matrix can be thick, creating the potential for excellent cabochons and carvings.

The uniqueness of this opal contributes to its rarity in the market, making it highly prized among collectors. Working with

Boulder Opal requires specialized knowledge and techniques, but the result can be a stunning masterpiece that endures forever.


Black Opal

Black Opals are some of the rarest and most valuable of all opals, featuring a deep, dark body color that allows the colors of the opal’s iridescence to pop and shine. The most famous source of

Black Opals is Lightning Ridge in New South Wales, Australia.

Black Opals have a distinctive color that sets them apart from all other opals. The precious opal inside the black body can range from cool blues and greens to warm reds and oranges.

Given its rarity and the high demand for it, black opals can be very expensive, often commanding premium prices among connoisseurs, jewelers, and collectors. Imitation black opals abound in today’s market due to their value and rarity.

These fake stones can be created through smoke or acid treatment or by adding some kind of dye. Buying opals only from trusted sources is thus crucial to ensure that you are acquiring genuine

Black Opals and not cheap imitations.


Black Opals are a precious variety, and it’s essential to handle them with the utmost care. The constant exposure of opals to moisture and sunlight can make them prone to crazing or cracking.

Sunscreen, oils, and cosmetics can also damage the stone over time. Hence, it is advisable to avoid too much exposure to these substances.


Matrix Opal

Matrix Opals are opals whose precious opal is interspersed in a matrix of sandstone or similar rock. This kind of opal is commonly found in the Andamooka field in South Australia and occurs in smaller particles than

Boulder Opals.

While they are similar to

Boulder Opals, the precious opal in

Matrix Opals is not as substantial.

Matrix Opals have a granular color and tenderness that makes them highly prone to developing crazes and cracks.

The sandstone matrix can also be unstable, and the opal within is subject to deterioration over time, making them challenging to use in jewelry.


Matrix Opals have a unique brightness that makes them attractive to collectors.

Due to their appearance, these opals are suitable for cabochons and carvings, making them a budget-friendly alternative to other kinds of opals. They have a range of colors, from blues and greens to reds and oranges, making them exciting and eye-catching.

A well-known variety of

Matrix Opal is the Louisiana sandstone opal. However, the supply of this opal is now limited, and mining has all but ceased in the area, making this type of opal highly prized and sought-after among opal collectors.

Despite their rarity,

Matrix Opals are not as valuable as other opals, and their instability makes them suitable mainly for collectors or enthusiasts.

In conclusion,

Matrix Opals are fascinating and unique stones that offer a budget-friendly option for those who love opals and their play of color.

While they have a granular brightness that makes them attractive, the sandstone matrix and instability of the opal within makes them challenging to work with and less valuable than other opals. It’s best to secure these precious opals from reputable dealers, and only purchase them when you have genuine interest in their special qualities.


Dendritic Opal

Dendritic Opal is a beautiful kind of opal that is distinguished by its milky, semi-transparent white base color and black dendrites, or metallic oxide inclusions. The dendrites give the stone a unique appearance similar to ferns or trees, making the stone appear like a work of art from nature.

The metallic oxides responsible for making the dendrites are usually iron oxide or manganese oxide, creating a stark contrast against the white background.

Despite its name,

Dendritic Opal is sometimes confused with Dendritic Agate, which shares a similar appearance due to the dendrites in the mineral.

Dendritic Agate, however, is a kind of quartz, while

Dendritic Opal is a form of silica. While the two stones are often confused, they are still vastly different.

Dendritic Opals can be easy to work with due to their inherent softness, which makes them perfect for cabochons or carvings. They do not have as much of a play of color as other opals, but their intricate patterns make for strikingly beautiful pieces.

Dendritic Opals originated from various mines, including Mexico, South America, and Australia. Other names used to refer to this stone include Merilinite or Merlinite, which can indicate that the stone has a rare and unusual pattern.


Fire Opal

Fire Opals are unique among opals because of their fiery flashes and brilliant color. They range in color from yellow to bright red and are almost exclusively found in two regions Mexico and Oregon.

The stones have a jelly-like transparency that makes them beautiful to look at, especially when backlit to reveal their vivid colors. In Mexico, much of the country’s

Fire Opal comes from the Quertaro and Hidalgo states.

Fire Opals are highly valued and expensive due to their rarity and delicate nature. As compared to other varieties of opals,

Fire Opals are fragile and are prone to developing cracks or crazes when exposed to changes in temperature or sudden movements.

They require extra care and handling to avoid damage.

While they are rare and precious, there are a few

Fire Opals with slightly lesser value.

These low-quality

Fire Opals may be treated to deepen their color and improve their transparency, so it’s important to purchase them only from reputable sources. Despite their value, gemstones experts consider

Fire Opal to be one of the more underrated gemstones in the market.

In summary,

Fire Opals are unique and striking gemstones that offer a varied range of colors with stunning brightness. Their rarity and fragility all add to their value, making them highly prized among collectors and jewelers alike.

It’s essential to treat these gemstones with extra care to preserve their value, making them a good investment for the future or a valuable addition to one’s jewelry collection.

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