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Opal Value: How Opals are Graded & Prices of Each Type

オパールの価値: オパールの等級と各タイプの価格

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Opals are unique from other gemstones in many ways, and that extends to how they’re graded. These gems have their own value grading criteria, though each type of opal may be valued more highly for different reasons than other types. 

All that said, opals can be one of the most difficult gemstones to value. The reason lies in their variability, as graders must consider the type of opal, its origin, color, brilliance, and many more factors. 

Is opal an expensive stone? It can be, but opal prices vary broadly among different varieties and quality levels. If you’re curious, the most expensive opal ever sold was the Fire (or Flame) Queen Opal, purchased by John D. Rockefeller in 1949 for £75,000, which translates to roughly $3,620,700 today! Another pricey specimen is the Virgin Rainbow, a huge, naturally glow-in-the-dark opal currently valued at over $1 million. 

How can you tell if an opal is valuable? The first step in knowing an opal’s value is learning how opals are graded and which properties to look out for. 

This guide will break down each opal value factor, grading terminology to know, the different types of opals, and what kind of prices to expect. 

How Are Opals Graded? 11 Value Factors

The value of an opal comes down to a multitude of factors, from standard gemstone grades like clarity and color to grades unique to opals like play-of-color and pattern.

How much is opal worth per carat? That depends on its quality and the factors we’ll discuss below. 

Unfortunately, there isn’t an overall opal value calculator that can tell you exactly how much an opal is worth, like there are for gems like diamonds. Instead, experts must take into account various value factors to determine what a particular opal is worth. 

There are some products that can help like the Opal Smart Chart software package, but at roughly $145, this isn’t accessible to everyone. That’s why we’ve created a guide to help you determine your opal’s value!

The 11 opal value factors we’ll break down are:

1. Type of Opal

2. Color (Body Tone)

3. Play-of-Color Directionality

4. Play-of-Color Pattern

5. Brightness

6. Clarity

7. Transparency

8. Shape or Cut

9. Country of Origin

10. Natural vs. Synthetic vs. Simulant

11. Treatments

When experts grade an opal, they do so under consistent conditions, often looking at the stone under incandescent light or daylight. When buying opals, it’s important to see the gem from every angle possible in multiple kinds of lighting.

The first step in grading opal value is determining what type of opal you’re looking at. 

Pictured above: Precious opals

1. Type of Opal

Some opals are simply more valuable than others, often because they’re rarer. 

There are many opal categories and sub-categories, but every type of opal falls under one of two overarching groups: precious opal vs. common opal. 

Precious opals display play-of-color and common opals do not. (Note: Play-of-color can also be called color-play, flashes, or fire). The difference is simple, but it plays a major role in an opal’s value. Overall, precious opals are almost always more valuable than common opals.

The color flashes reflected can also affect value. Predominantly red and orange flashes are rarer and more valuable than violet and blue flashes, especially in precious black opals. 

Outside of the precious vs. common distinction, opal grading is also separated by factors like their origin, inclusions, assembly (i.e. doublet, triplet, mosaic), formation (natural vs. synthetic), and body tone.

2. Color (Body Tone)

In general, color is the top factor for an opal’s value. Grading an opal’s color means looking at its body tone, meaning the base or background color. As such, “body tone” is sometimes called “background color” or “base tone.” 

Body tone is separate from play-of-color and brightness, but it can affect both. Darker body tones will allow the color play to appear brighter than it does on lighter body tones, making darker-colored precious opals more valuable than lighter-colored ones. 

Luckily, the Opal Association of Australia created a handy body tone guide for easier classification. 

The tones go from N1 to N7 or N9, depending on who is grading. N1 to N4 always describes black body tones. N5 to N7 may describe lighter-colored opals, but those who use the N1-N9 chart describe N5 and N6 as dark opals and N7 to N9 as light/white opals. 

This grading classification follows the three basic types of opals: black, dark/gray, and light/white. Of course, that doesn’t account for other opal colors, which usually come down to their rarity. Warm hues are rarer, while greens and blues are more common. Purples and violets are rare, but not as valuable as reds or oranges. 

Additionally, the tone and saturation of an opal’s body tone affects its value. Purer hues with brighter saturation are valued more highly than lighter, duller, or impure hues (i.e. colors with undertones). 

You can see the Opal Body Tone chart above.

3. Play-of-Color: Directionality

Displaying play-of-color already makes an opal more valuable, but lots of opals display this fiery effect. Certain aspects of the play-of-color make some of those precious opals more valuable than others, like directionality.

Directionality refers to the brightness of an opal’s play-of-color only being visible from certain angles. A non-directional precious opal (sometimes called “full-face”) will display the same level of brightness from any direction. These are quite valuable but rare. 

The other degrees of directionality are often graded as:

• Slightly Directional: The brightness shifts slightly at different angles but doesn’t change more than one brightness level (we’ll discuss brightness levels later on)

• Somewhat Directional: The brightness shifts at least one brightness level in certain directions

• Very Directional: The brightness is mostly lost in certain directions

• Highly Directional: The brightness is entirely lost in certain directions, often only bright in one direction

Most opals will show some degree of directionality, but less directionality means higher value. If they lose brightness from a front-facing angle, this can be more detrimental to value than losing brightness from a side angle. 

The type of opal jewelry may also factor into the ideal directionality. An opal that is brightest from peering at it straight-down makes a better ring, while an opal that looks brightest when vertical makes a better pendant. 

Another aspect of color-play is any pattern that emerges on the opal. 

4. Play-of-Color: Pattern

Pattern refers to the shapes and arrangements of an opal’s play-of-color. There are dozens of patterns that you can see and learn about in our opal patterns guide. 

Pattern can also take into account the play-of-color distribution; a more evenly spread color distribution is better than localized patches of color-play. Patterns with extinction, or “dead spots” where no color-play is visible, are less valuable. 

While a pattern’s desirability is largely up to taste, one stands out as the rarest and most valuable: the harlequin pattern. 

Harlequin opals have a repeating pattern of contracting squares or diamonds. The rarest types have a red harlequin pattern on a black opal; this type has only been found in Lightning Ridge, Australia, and can go for $5,000 to $30,000 per carat. 

Other rare, valuable patterns include:

• Sunburst/Starburst

• Flagstone

• Fingerprint

• Neon flash

• Mackerel

• Cathedral

• Chinese writing

• Rolling fire

• Windmill

In general, broad, large patterns like flagstone are more valuable than small, close-together ones like pinfire. 

Regardless of pattern, brighter color-play is key to opal value. 

5. Brightness

Brightness is arguably the most important factor in an opal’s value, after body tone. Sometimes brightness is even more important than body tone, as is the case with black opals. 

A brighter opal with only a couple of colors in its color-play is often more valuable than a dull opal with many color flashes. 

Brightness is much more straightforward than factors like patterns or directionality. Like body tones, brightness grades are classified with a handy chart created by the Australian Opal Association. 

The grades of opal brightness start from the brightest at B1 to the dullest at B7. B1 is often called “brilliant,” while B2 to B3 are “bright” and B4 to B7 are “subtle.” 

You can see the Opal Brightness chart above.

6. Clarity

Clarity describes the amount of visible inclusions in a gem. Some graders combine it with transparency when giving a clarity grade because the two properties can influence each other.

Besides internal inclusions, clarity can also encompass external blemishes like cracks and crazing. Crazing and cracks are similar, but crazing describes a web-like network of cracks resulting from moisture loss.

Another sort of inclusion is a matrix, meaning an opal is intermixed into the rock it formed within (its “host rock”). A matrix usually means lower value, though there are some exceptions. 

The more visible inclusions and blemishes an opal has, the lower its clarity grade and value. Crazed opal value in particular is typically only 10 to 20 percent of a similar-quality opal that isn’t crazed, if it’s even sold at all. Cracks on the opal’s face (the top, most visible portion) also often make opals worth little to nothing. 

Besides inclusions, cracks, and crazing, other potential opal blemishes include:

• Pits

• Fractures

• Fissures

• Gray webbing lines

• Windows (little to no color or reflection in the center of a faceted opal)

• Potch lines (thin lines of common opal, or “potch,” intersecting the play-of-color on the face of a precious opal)

Potch lines don’t always significantly lower value; they can sometimes create attractive patterns. Other inclusions can similarly lead to desirable types of opals, like dendritic opal. 

Pro Tip: Don’t buy opals sold in water. Most opals are porous enough to absorb the water, seemingly increasing its carat weight. More importantly, the water absorption can disguise blemishes and cracks. 

7. Transparency

Transparency is how much light passes through a gemstone. Opals can range from fully transparent to opaque. However, the majority of opals are opaque to translucent. 

The rare transparent opals — like water opals, crystal opals, and fire opals — are generally more valuable, but certain opal types (like black opal) are better opaque. Cloudiness generally lowers value. 

8. Shape or Cut

Like clarity, cut is one of the standard gemstone grading factors that applies to opal value. 

What is the best cut for opal? Most opals are cut into cabochons, though one exception is fire opals, which are commonly faceted. Faceting can negatively affect many opals’ durability and play-of-color.

The best opal cabochons:

• Are symmetrical

• Are not too thin or too thick (generally at least 2mm unless it’s cut for use as a doublet/triplet)

• Have a well-rounded, full, smooth dome with no points or dents (unless it’s a sugarloaf cabochon)

• Display maximum play-of-color with no directionality

• Not too wide or too narrow (if oval)

Abundant opals like common white opals are often cut into calibrated sizes (ones that fit standard size jewelry settings without needing customization) like 6x4mm, 7x5mm, or 8x6mm. Other varieties like boulder opals may necessitate a freeform shape. 

Pictured above: Green Peruvian opal

9. Country of Origin

An opal’s source doesn’t always influence its value, but it can be a factor. Australia is the number-one opal producer, sourcing roughly 95 percent of the world’s opals. Ethiopia is the second largest opal producer. 

Some opal varieties are exclusive to certain sources, many of which are areas in Australia. Plus, certain mines have gained reputations over time for producing high-quality opal rough. These are both reasons why Australian opals tend to be more expensive. 

But while Australian and Ethiopian opal prices can be steep, all the other factors must be taken into account for each opal. 

Pictured above: Dragon's Breath opal

10. Natural vs. Synthetic vs. Simulant

Synthetic opals are created in a lab to have the same physical and chemical properties as natural material. Simulants or imitation opals are materials unrelated to opals that resemble them in appearance, like glass or resin. 

Natural opals are always more valuable than synthetics or simulants. While synthetic opals are generally only a few dollars, they’re still more valuable than simulants. 

Synthetic opals come in virtually any color and often show intense color-play Some synthetic opal varieties include:

• Opalite

• Sterling Opal (Monarch Opal) 

• Dragon’s Breath Opal

• Aurora Opal

Note: “Opalite” can also refer to a natural green opal with dendritic inclusions. 

Pictured above: Smoked Ethiopian Welo opal

11. Treatments & Composites

While opals aren’t treated as often as other gems like sapphires, there are a number of opal treatments. Treated opals are less valuable than untreated opals. 

Opal treatments include:

• Sugar & Acid: Most common opal treatment, often done to Andamooka matrix opals 

• Smoking: Common for creating “black” Ethiopian opals from hydrophane specimens or for darkening matrix opals

• Dye: Common for certain Ethiopian opals, usually to create “black” opals

• Resin Treatment: Sometimes done on Queensland boulder opals to better bond the opal layer to the host rock 

• Fracture Filling / Oiling: Common for many opals with blemishes like crazing; Oiling with Opticon somewhat common for hydrophane opals and for stabilizing crazed opals

• Surface Coating: Newer chemical vapor deposition (CVD) treatment done on some Queensland boulder opals to improve durability

Most opal treatments are done to create “black” opals, given this variety’s high value. Ethiopian hydrophane opals are quite porous and absorb easily, making them popular specimens for treatments. Most Andamooka matrix opals undergo sugar & acid treatments. 

Sellers should always disclose treatments, but you can also test for some opal treatments yourself. 

Another opal alteration involves taking natural opals and adding synthetic materials to create composite opals: doublets, triplets, mosaic, and chip opals. Natural opals that aren’t composites (or “assembled”) are called solid opals. 

Normally, doublet opal value will be 15 to 35 percent of the price of solid opals of similar appearance, though top-quality doublets can reach 50 percent of similar-looking solid opal prices. Triplet opal value is significantly lower, only around 1 percent of the price of similar-looking solid opals. 

Next, let’s look at how all of the elements above factor into an opal’s grade. 

What Are The Grades of Opals?

Unlike the established grades of popular gems like diamonds, there aren’t official grades for opals. Still, different sellers and industry leaders have created their own opal grades. 

First, we’ll look at the opal grade categories from the International Gem Society (IGS). 

IGS Opal Grading

The International Gem Society has 5 categories of opal grades created by opal expert Dr. Paul Downing, outlined below in order of least to most valuable. 

These categories take into account color (both body tone and play-of-color), directionality of play-of-color, cut quality, and imperfections (a.k.a. clarity and transparency). 

Extra Fine opal value per carat will be considerably higher than Below Commercial. 

• Below Commercial: Faint color, low brightness; Very little & very directional play-of-color; Cut is uneven, too thick, or not thick enough; Substantial visible inclusions or matrix

• Commercial: One to two colors, dull brightness; Very to somewhat directional play-of-color; Uneven surface, too thick, not thick enough; Some visible inclusions

• Good: Multiple colors, good brightness; Somewhat to slightly directional play-of-color; Good to excellent cut; Minor visible inclusions

• Fine: Multiple colors, great brightness; Slightly directional or non-directional play-of-color; Good to excellent cut; No visible inclusions to the naked eye

• Extra Fine: Every color, brilliant brightness; Non-directional play-of-color visible from all directions; Good to excellent cut; No inclusions visible under 10x-magnification

Opals may seem to fit more than one of these categories. In that case, the most important factors are the body tone and play-of-color. If the properties are split between two grades, it may be appropriate to choose a grade between the two (e.g. properties split between Commercial and Fine could mean Good).

Other Opal Grades

Outside of the IGS appraisal system, other sellers may use their own opal grades. One common system is grading from AAAA to A, or Heirloom to Good:

• Heirloom (AAAA): Top 1 percent; Opaque, blemish-free, intense play-of-color

• Best (AAA): Top 10 percent; Opaque, very slight blemishes; Medium play-of-color

• Better (AA): Top 33 percent; Opaque, slight blemishes; Low play-of-color

• Good (A): Top 75 percent; Opaque, surface blemishes, No play-of-color

IGS grades are more well-established, so we recommend following those over other opal grades. 

Now that you know the opal grading factors and categories, let’s go over opal prices per carat for each opal variety. 

Types of Opals and Their Value: Prices of Each Variety

By now, you know the first factor of opal value is the type of opal. Opal varieties are quite diverse, separated by factors like origins and body tones. 

You may wonder: what color is the most valuable opal? That would be precious black opals, the most sought-after variety. Among common opals, red is rarest. 

But we’ll start with the prices of a much more affordable variety: white opal.

White Opal

White or light opal is the most common opal color, making it a more affordable option. That said, white opal price per carat ranges vary broadly. 

A low-quality white opal can be as low as $10 per carat. These are often cloudy and opaque with no color-play. Meanwhile, top-quality white opals can reach $6,000 per carat. 

Top-quality white opals are closer to transparent, are free of visible inclusions, and display excellent play-of-color with intense, non-directional brightness. 

Still, the light background of white opals means play-of-color can never show as brightly as dark opals. 

White opal prices per carat range by their grade and body tone (N7 to N9):

• N7 Opals: $10 to $2,400 per carat (mid-range $150 to $500 per carat)

• N8 Opals: $10 to $2,200 per carat (mid-range $70-$250 per carat)

• N9 Opals: $1 to $2,000 per carat (mid-range $15 to $90 per carat)

Shifting to the other side of the body tone chart, we have black opals. 

Black Opal

Black opals are the rarest, most valuable opal variety. They can be gray, black, or even dark blue sometimes, so they’re also called “dark opals.” Part of black opal’s value lies in the contrast between the dark background and bright play-of-color. 

For this variety’s value, brightness is more important than body tone and opaque stones are more valuable than transparent black crystal opals. 

The black opal prices for N1 to N4 stones range from $10 to $20,000 per carat for 1- to 10-carat stones and $10 to $16,000 per carat for stones over 10 carats. Mid-range quality black opal prices range from $300 to $1,400 per carat. 

Black opal value for N5 to N6 stones (“dark opals”):

• 1 to 5 carats: $10 to $5,000 per carat 

• 5 to 10 carats: $10 to $7,000 per carat

• 10+ carats: $10 to $6,400 per carat

Mid-range quality dark opals go for $300 to $1,200 per carat regardless of carat weight.

Colored Common Opals

Prices for colored common opals (with no color-play) mostly range by rarity: 

• Green: $0.40 to $15 per carat

• Purple (Morado): $0.50 to $5 per carat

• Blue: $50 to $250 per carat

• Pink: $0.50 to $150 per carat

What about red, orange, and yellow? Those all count as fire opals! 

Fire Opals

Opals that are red, orange, yellow, or a combination of these colors are called fire opals. They can be common or precious, the latter being rarer and pricier. The most valuable fire opals are transparent, uniformly colored, and bright red-orange or red. 

The most famous specimens are Mexican fire opals, but Australia and Ethiopia also produce fire opals. Fire opals are also unique in typically being translucent to transparent and commonly faceted.  Mexican specimens tend to be common fire opals, while Ethiopia produces more valuable precious fire opals with neon violet and green color-play. 

Faceted fire opal prices range from $10 to $250 per carat. Fire opal cabochon prices are between $25 to $300 per carat, or $25 to $135 per carat if they’re in-matrix. 

Transparent Opals: Crystal, Jelly, Contraluz & Hyalite

Though transparency in opals is rare, there are a few varieties known for being colorless and transparent: crystal opal, jelly opal, contraluz, and hyalite. 

Crystal opal is the second most valuable opal after precious black opal. This precious opal type is colorless, transparent, not milky, and ranks at N7 to N8 on the body tone scale. 

Here are the crystal opal prices by carat weight ranges:

• 1 to 5 carats: $2 to $6,000 per carat 

• 5 to 10 carats: $2 to $6,400 per carat

• 10+ carats: $2 to $6,000 per carat

Next are jelly opals, also called water opals. These are colorless, transparent precious opals with a gelatinous appearance. They’re slightly darker than crystal opals. 

Jelly opal value typically ranges from $5 to $140 per carat. 

Contraluz opals are colorless precious opals with color-play seemingly floating inside when you illuminate them from the back. 

Contraluz opal prices range from $150 to $200 per carat. 

Last up is hyalite, a colorless, pale yellow or green common opal type with strong green fluorescence. Hyalite opal prices range from $6 to near $1,000 per carat. 

Boulder & Matrix Opals

Boulder opal is an ironstone or sandstone with patches and/or thin seams of precious opal attached naturally. Matrix opal is similar, but the precious opal fills holes or pores between the rock’s grains, creating a larger distribution of color-play throughout. 

Boulder and matrix opal prices are in the same category:

• 1 to 5 carats: $10 to $1,000 per carat (mid-range $100 to $180 per carat)

• 5 to 10 carats: $10 to $2,000 per carat (mid-range $90 to $200 per carat)

• 10 to 15 carats: $10 to $5,000 per carat (mid-range $120 to $400 per carat)

• 15+ carats: $10 to $8,000 per carat (mid-range $200 to $600 per carat)

Certain subtypes may be pricier, like Yowah nuts. 

Composite Opals: Doublets & Triplets

Doublets and triplets are a budget-friendly alternative to solid opals. Almost any opal can be made into a doublet, so prices vary by the type of opal used. 

Here at Opal Auctions, our doublet opals range from $0.90 to around $230 per carat. Our triplet opals range from $1 to roughly $170 per carat. 

Synthetic Opals

Another budget-friendly option is a synthetic opal. There are some popular types of synthetic opals to choose from, too. 

Aurora opals are generally under $1 per carat. Synthetic opalite gems are generally $1 to $3 each. Dragon’s breath opals start around $4 and reach $75 each. Sterling (or Monarch) opals start around $4 and reach $450 each. 

Ready to Find the Optimal Opal for You?

As you can see, grading opal value is complex, but that’s only because opals are such uniquely diverse gems. Knowing what goes into opal value and opal grading can help you feel confident that you’re getting the best deal possible. 

Browse our array of opal gemstones today!