Opal Never Does the Same Thing Twice.

Natural Opals

There is no single way an opal is supposed to look.

That is probably the reason we keep coming back to them.

One stone may show broad flashes of red and green.

Another may carry tiny pinpoints of color across the entire surface.

Some are transparent.

Some are milky.

Some have a dark body tone that makes the color look almost electric.

Others barely show anything until you move them into the right light.

And some, like hyalite, can look almost understated until ultraviolet light completely changes the experience.

At Caleb B. Quashen International, we choose opal the same way we choose most of our gemstones.

We look at the actual stone.

The color.

The pattern.

The body tone.

The transparency.

The stability.

The fluorescence, when it matters.

And whether it does something worth remembering.

What Makes Opal Different?

Opal is unlike most of the gemstones we work with.

It is hydrated silica rather than a crystalline mineral like sapphire, diamond, or beryl.

Fine precious opal is known for play-of-color — flashes of spectral color created when light interacts with tiny, ordered silica spheres inside the material.

That structure is why an opal can show red, orange, yellow, green, blue, and violet even when the material itself has a completely different body color.

And because those internal structures are never arranged exactly the same way twice, every stone behaves differently.

That is not marketing.

That is the material.

Play-of-Color

Play-of-color is usually the first thing people notice in a fine opal.

But not all play-of-color looks the same.

Some stones show broad flashes.

Some show pinfire.

Some have rolling areas of color that move across the surface as the stone turns.

Others show distinct patches, stripes, or patterns that are visible only from certain angles.

The strength, distribution, pattern, and range of color all matter.

Red is often considered especially desirable, but we do not judge an opal by one color alone.

A stone covered in bright green and blue can be incredible.

So can a quieter opal with one unexpected flash that only appears when you move it.

You have to look at the whole stone.

Australian Opal

Australia has been one of the most important sources of precious opal for generations and produces several very different types of material.

White opal.

Black opal.

Crystal opal.

Boulder opal.

Each behaves differently.

Black and darker body tones can create dramatic contrast, making the play-of-color appear even more intense.

White opal tends to feel softer.

Crystal opal can be transparent to translucent, allowing color to seem suspended inside the stone.

Boulder opal often retains part of the ironstone matrix it formed in, which can become part of the finished gem rather than something to remove.

We especially like that last category.

Sometimes the host rock is part of the reason the stone works.

Ethiopian Opal

Ethiopian opal changed the market.

The Wollo region has produced large quantities of precious opal with strong play-of-color, unusual patterns, and a wide range of body tones.

A lot of Ethiopian opal is hydrophane.

That means the stone can absorb water.

And that matters.

When a hydrophane opal takes in water, its transparency, appearance, and play-of-color can temporarily change.

Some material may also be more sensitive to liquids, oils, dyes, and rapid environmental changes.

That does not make Ethiopian opal bad.

It means you need to understand what you are working with.

Hyalite Opal

Not every opal is about play-of-color.

Hyalite opal can look almost completely different from the material most people picture when they hear the word opal.

It is often transparent to translucent, sometimes nearly colorless, and can carry subtle white, yellow, orange, or brown tones.

What makes certain hyalite especially interesting is fluorescence.

Some material can produce an intense green response under ultraviolet light, turning a stone that looks understated in normal lighting into something completely different.

We like that contrast.

A clean hyalite may not show the rolling spectral flashes of precious opal, but it can have exceptional clarity, unusual fluorescence, and a presence that feels more like looking through the stone than across its surface.

That is a different kind of opal.

And one we think deserves its own attention.

What Is Hydrophane Opal?

Hydrophane opal is porous enough to absorb water or other liquids.

The effect can be surprising.

A stone may become more transparent.

The play-of-color may change.

It may temporarily appear duller or brighter.

Then, as the moisture leaves the stone, it can return toward its previous appearance.

Because hydrophane material can absorb liquids, it also requires more care around oils, chemicals, dyes, and prolonged soaking.

This is one of the areas where knowing your opal matters just as much as loving the color.

Body Tone Changes Everything

Play-of-color gets most of the attention.

Body tone changes the entire experience.

A darker opal can make flashes of color look more intense because of the contrast underneath them.

A white or pale opal may feel softer.

A transparent crystal opal can create depth because you are seeing both into and through the material.

A brown or honey-toned Ethiopian opal can make the play-of-color feel completely different again.

There is no best body tone.

There is only the stone in front of you.

Matrix Is Not Something We Automatically Remove

Some opals form with the host rock still attached.

Boulder opal is the best-known example.

That matrix can create brown, black, or earthy areas within the finished stone and may guide the entire outline of the cut.

We like material like that because the geology stays visible.

The stone does not look as though it could have come from anywhere.

It still carries part of where it formed.

That is worth preserving when it works.

Cutting Opal Is About Following the Color

Opal rough can be frustrating.

And incredibly rewarding.

A promising color bar may disappear if you cut too deep.

The strongest play-of-color may sit just beneath the surface.

A thin seam may dictate the entire final shape.

With boulder opal, the matrix may tell you exactly how much material can be removed before the best part disappears.

With hyalite, transparency and shape may matter more than chasing play-of-color at all.

That means the cutter cannot simply impose a standard shape and hope for the best.

You follow the color.

You follow the layer.

You follow the transparency.

You remove what needs to go.

And sometimes you stop sooner than you expected because the stone is already doing exactly what it should.

That is why opals so often end up in freeforms, irregular cabochons, or shapes that would make little sense in another gemstone.

The rough is making the decision.

Not Every Opal Has Play-of-Color

There is also common opal.

Common opal does not display the spectral play-of-color associated with precious opal, but that does not mean it cannot be beautiful.

Blue opal.

Pink opal.

Green opal.

Fire opal.

Hyalite.

Other material may be valued primarily for body color, transparency, fluorescence, texture, or pattern rather than rainbow flashes.

We like opal in both forms.

Again, it comes down to the stone.

Natural Opal & Treatment

Opal can be treated in several ways.

Some material may be dyed.

Darkened.

Impregnated.

Smoked.

Or assembled into doublets and triplets to improve appearance or durability.

Hydrophane Ethiopian material deserves particular attention because its porosity can make it receptive to dyes and other substances.

We disclose known treatment and construction information on the individual listing.

If it is natural solid opal, we say so.

If it is treated, assembled, or otherwise modified, that needs to be clear too.

Opal Requires a Little More Care

Opal is not sapphire.

It is not diamond.

It is a softer material, generally around 5 to 6.5 on the Mohs hardness scale, and its water content and internal structure mean it needs thoughtful care.

Hard impacts can damage it.

Extreme temperature changes are not ideal.

Hydrophane opal should not be routinely soaked.

And ultrasonic or steam cleaning is generally not how we would treat a stone like this.

None of that means opal cannot be worn.

It just means the jewelry should respect the material.

Choosing a Loose Opal

Opal is one of the gemstones we most strongly recommend seeing in motion.

A still photograph may show one moment.

The stone may have twenty more.

You want to see how the color moves.

Where the strongest flashes appear.

Whether the pattern covers the entire face or concentrates in one area.

How the body tone changes in daylight.

Whether the stone fluoresces.

And whether the material has any stability or durability considerations that matter for the final design.

That is especially important if the opal is intended for a ring.

An unusual freeform may need a custom setting.

A boulder opal may already have a natural edge worth preserving.

A crystal opal may look best with light allowed through the back.

A hyalite may deserve a design that lets its transparency and fluorescence remain part of the experience.

Start with the opal.

Then build around what it actually does.

Why We Buy Opal

We do not buy opal because it photographs well.

Some of the best opals are actually terrible at sitting still for a picture.

We buy them because of what happens when you move them.

A flash that was not there a second ago.

A color you did not expect.

A strange pattern.

An area of matrix that makes the whole stone work.

A clear hyalite that turns electric green under UV.

Or a piece of rough that forces the cutter to follow a path that was not obvious at the beginning.

Opal rewards attention.

That is probably why we keep staring at it.

Opal Questions

What causes play-of-color in opal?

Play-of-color is caused by diffraction of light through ordered arrays of microscopic silica spheres inside the opal.

The size and arrangement of those spheres determine which colors become visible.

What is the difference between Australian and Ethiopian opal?

The two origins can produce very different material.

Australian opal commonly includes white, black, crystal, and boulder opal and is generally non-hydrophane.

Much Ethiopian Wollo opal is hydrophane, meaning it can absorb water and temporarily change in appearance.

What is hyalite opal?

Hyalite is a transparent to translucent variety of opal that often shows little or no play-of-color.

Some hyalite is especially prized for strong green fluorescence under ultraviolet light.

Does hyalite glow under UV light?

Some does.

Certain hyalite opals contain trace elements that can produce very strong green fluorescence under ultraviolet light.

The strength of the reaction varies by stone.

What is black opal?

Black opal has a dark body tone that creates strong contrast with the stone’s play-of-color.

The term refers to body tone, not an opal that is simply black throughout.

What is boulder opal?

Boulder opal forms within or alongside ironstone host rock.

The opal layer is often cut with part of that natural matrix left attached, becoming part of the finished gemstone.

What is hydrophane opal?

Hydrophane opal is porous opal that readily absorbs water or other liquids.

This behavior is especially common in Ethiopian Wollo material and can temporarily change transparency and play-of-color.

Is Ethiopian opal less valuable than Australian opal?

Not automatically.

Origin is one factor, but play-of-color, pattern, body tone, transparency, size, stability, treatment, and overall appearance all influence value.

Are opals treated?

Some are and some are not.

Treatments can include dyeing, darkening, impregnation, and other processes. Opals may also be assembled as doublets or triplets.

We disclose known treatment or construction information on the individual listing.

Are opals good for engagement rings?

They can be used in engagement rings, but they require more care than harder gemstones such as sapphire or diamond.

The individual opal, setting style, lifestyle of the wearer, and whether the material is hydrophane should all be considered.

Can CBQ source a specific opal?

Yes.

If you are looking for a particular origin, body tone, play-of-color pattern, fluorescence, size, shape, matrix style, hyalite, or other type of opal, contact us and tell us what you have in mind.