How to Buy Opal: What Really Determines Quality?

How to buy opal becomes much easier once you stop looking for a single sign of quality. Unlike gemstones that are often judged heavily by clarity, color, and cut, opal has an additional world of characteristics to consider: play-of-color, brightness, pattern, body tone, transparency, color distribution, construction, treatments, stability, and origin can all influence what makes one stone different from another.

In Part 1 of our Deeper Opal Learning Series, we explored why precious opal changes color and how its microscopic structure produces play-of-color. In Part 2, we compared Australian and Ethiopian opal, including hydrophane behavior and important differences in care. Now we're bringing everything together with the most practical question of the series: what should you actually look for when buying opal?

There is no single "best" opal for everyone. A collector searching for an exceptional black opal may prioritize very different characteristics from someone choosing a delicate white opal pendant or colorful opal beads. The goal is to understand what you're seeing—and make sure the price and description reflect what the gemstone actually is.

Start with Play-of-Color

When buying precious opal, play-of-color is one of the first characteristics to examine.

Don't simply ask whether the stone contains rainbow colors. Look at how those colors behave.

Are they bright and easily visible?

Do they appear across much of the gemstone, or only in one small area?

Do the colors remain visible from several viewing angles?

Does the display become noticeably weaker when the opal is moved?

An opal with vivid, well-distributed play-of-color can be visually impressive even if it doesn't contain every spectral color.

Brightness is particularly important. Strong, lively flashes can often have more visual impact than a wider range of weak colors.

And remember: common opal does not display play-of-color at all. Pink opal and other common opal varieties should be evaluated according to characteristics appropriate to that material rather than being judged as inferior precious opal.

Look at the Colors—But Don't Judge by Red Alone

In precious opal, blue and green are commonly encountered, while yellow, orange, and red can add considerable visual interest. Strong red play-of-color can be especially desirable.

But buying opal based only on whether you see red is a mistake.

Imagine one opal with a tiny, weak red flash visible from a narrow angle and another with brilliant blue and green covering almost the entire face. The first stone isn't automatically better simply because red is present.

Consider brightness, distribution, contrast, pattern, and overall appearance together.

The most appealing opal is often the one whose colors work beautifully as a complete display rather than the one that simply checks a particular color box.

Understand Body Tone

An opal's body tone is the underlying lightness or darkness of the gemstone, separate from its play-of-color.

This is what creates the visual foundation behind the spectral flashes.

Black and dark opals provide a deeper background that can create dramatic contrast with bright play-of-color. White and light opals produce a softer overall appearance.

Fire opal takes another direction, with body colors ranging through yellow, orange, and red. Some fire opals display play-of-color, while others do not.

One body tone is not automatically right for every buyer.

Instead, consider how effectively the body color works with the gemstone's play-of-color and how the finished opal will look in its intended jewelry design.

Pattern Can Make an Opal Extraordinary

Once you've examined brightness and color, look at how the colors are arranged.

Opal patterns can range from tiny pinpoints to broad flashes, patches, rolling areas of color, and more distinctive organized displays.

Certain unusual patterns are particularly sought after by collectors, but attractive pattern does not need to fit a famous trade name.

Ask yourself whether the pattern feels balanced across the stone.

Does movement reveal new areas of color?

Is there one spectacular section surrounded by mostly inactive material?

Does the pattern complement the shape and orientation of the cut?

This is one area where seeing an opal in motion can be extremely useful. Still photographs may not communicate the complete pattern because play-of-color changes with viewing angle.

Transparency Changes the Character of Opal

Opal can range from opaque to transparent.

In crystal opal, transparency or semi-transparency can create the impression that flashes of color are suspended within the gemstone.

Other opals may be much more opaque, with play-of-color appearing strongly against a white, dark, or colored body.

Neither transparency nor opacity automatically determines quality.

Instead, evaluate whether the transparency works with the gemstone's body tone, brightness, color, and pattern.

A beautiful transparent crystal opal and an exceptional opaque black opal succeed for completely different visual reasons.

Examine the Cut

Cutting opal is very different from cutting many transparent crystalline gemstones.

Precious opal is frequently fashioned into cabochons, where a smooth domed surface allows play-of-color to remain prominent.

A skilled cutter considers the orientation of the color within the rough and attempts to position the strongest display where it can be seen from the face of the finished gemstone.

Look at the overall proportions.

Is the shape balanced?

Is the surface polished well?

Does the orientation show the color effectively?

Is the dome appropriate for the material?

An unusual freeform shape is not automatically poor cutting. With opal, preserving an exceptional area of color may be more important than forcing valuable rough into a perfectly standardized shape.

Solid Opal, Doublet or Triplet?

Before comparing prices, determine what you're actually buying.

A solid opal consists of opal material rather than intentionally assembled layers.

An opal doublet generally combines a relatively thin layer of precious opal with a dark backing. The backing can increase contrast and make the play-of-color appear stronger.

An opal triplet typically adds a transparent protective dome over a thin opal layer and backing.

Doublets and triplets can make attractive jewelry and allow buyers to enjoy vivid opal at more accessible prices. They are not inherently bad products.

But they are not equivalent to solid natural opal and should be clearly disclosed.

Also remember that boulder opal is not automatically a doublet. In natural boulder opal, the opal occurs naturally attached to its host rock. An assembled doublet is intentionally bonded together by people.

Ask About Treatments

Treatment disclosure is another important part of buying opal.

Some opals may be treated to darken their body color or alter their appearance. Treatments can include processes involving smoke, sugar-and-acid methods, dyes, coatings, impregnation, or other techniques depending on the material.

Treatment does not necessarily make an opal unattractive, but it can affect value, durability, identification, and care.

A seller should disclose known treatments rather than allowing the buyer to assume that the gemstone's appearance is entirely natural.

This becomes especially important when a stone has unusually dramatic color or contrast at a price substantially below comparable untreated material.

An unusually good deal is not proof of treatment—but it is a good reason to ask better questions.

Natural vs. Laboratory-Grown Opal

You should also know whether an opal is natural or laboratory-created.

Laboratory-grown opal can reproduce the characteristic play-of-color associated with natural precious opal. It should be disclosed as laboratory-created or synthetic rather than sold simply as natural opal.

Imitation opal is different again.

An imitation may be made from glass, plastic, resin, or another material designed to resemble opal without actually possessing the same fundamental material characteristics.

This is why the question "Is it real?" isn't specific enough.

Ask whether it is natural opal, laboratory-grown opal, an imitation, or an assembled product such as a doublet or triplet.

Consider Origin—but Don't Buy the Country Name

As we explored in Part 2, Australia and Ethiopia are both important sources of natural precious opal.

Australia is famous for varieties including black, white, light, and boulder opal. Ethiopia produces beautiful precious material, much of which is hydrophane and can absorb water.

Origin can influence rarity, care considerations, collector interest, and sometimes market value.

But country of origin does not replace quality.

A mediocre Australian opal is not automatically better than an exceptional Ethiopian opal simply because Australian opal has a long-established reputation.

Evaluate the individual gemstone first and origin second.

And if an expensive opal is being sold with a specific origin claim that significantly increases its value, consider how that origin was established.

Check the Opal's Condition

Beautiful play-of-color can easily distract buyers from inspecting the physical condition of an opal.

Look closely for cracks, chips, damaged edges, significant scratches, and crazing—a network of fine fractures that can develop in some opal.

A natural inclusion or irregularity is not automatically a durability problem, but an existing fracture deserves attention.

For jewelry, also examine the setting. Does it adequately protect vulnerable edges? Is the stone secure?

Rings and bracelets generally encounter more impact than pendants and earrings, so durability and setting design become especially important when choosing opal for frequent wear.

Think About How You'll Actually Wear It

The "best" opal also depends on its purpose.

For an opal ring, protection matters because hands regularly encounter hard surfaces. A setting that provides some protection around the gemstone may be preferable for everyday wear.

Opal earrings and pendants typically receive less physical impact, allowing more flexibility in design.

With opal beads, examine not only color but also consistency, bead shape, polish, drilling, size, and how the individual beads have been arranged within the strand.

Natural variation can be part of the beauty of gemstone beads. The goal does not necessarily need to be perfect uniformity, especially when the material itself naturally varies in color and pattern.

What Questions Should You Ask an Opal Seller?

Before purchasing an important opal, try to establish the full description of the gemstone.

Ask:

• Is this natural or laboratory-grown opal?
• Is it solid opal, a doublet, or a triplet?
• Has it received any known treatment?
• What type of opal is it?
• Does it display play-of-color?
• Is the geographic origin known?
• If Ethiopian, is it hydrophane?
• Are there any cracks, crazing, or durability concerns?
• Are important origin or treatment claims supported by gemological documentation?

You won't necessarily need every question for every inexpensive bead or small jewelry piece. But as price and rarity increase, accurate identification and disclosure become increasingly important.

Buy the Opal, Not Just the Description

Perhaps the most important advice for learning how to buy opal is simple: evaluate the individual gemstone rather than buying a famous name.

"Black opal," "Australian opal," "Ethiopian opal," and "crystal opal" can tell you useful things, but none guarantees exceptional quality.

Look at brightness. Watch the play-of-color move. Consider the pattern. Examine the body tone, transparency, cut, condition, and construction. Understand treatments and ask whether the opal is natural.

Then consider the characteristic that is harder to put into a grading chart: do you actually love the way this particular opal looks?

Opal is extraordinarily individual. Two stones of similar size and origin can produce completely different visual experiences.

That individuality is exactly why learning how to evaluate opal is more useful than searching for one universally "perfect" variety.

And with that, our second three-part Opal Learning Series is complete: Why Does Opal Change Color? → Australian vs Ethiopian Opal → How to Buy Opal.

Together with our original series—What Is Opal? → Types of Opal → How to Tell if Opal Is Real—these six guides build a much deeper foundation for understanding opal, from its formation and identification all the way to choosing one confidently.