Opal Gemstone Information

Introduction to Opal Gemstones

Opalescent - that word captures something truly captivating, doesn't it? It evokes images of brightness, brilliance, shimmer, and sparkle. This term emerged because nothing else could quite describe the dazzling play-of-color in opals: think flaming reds against a milky backdrop or neon greens shifting like waves.

Opals stand among the oldest gemstones cherished by humanity, alongside diamonds, rubies, sapphires, emeralds, and pearls. They flash rainbow hues as you tilt them, thanks to a unique play-of-color effect. These gems often contain up to 20% water and form from silica spheres in rock cracks, clay layers, or even fossils.

Many consider opals the most mesmerizing gem due to their mysterious color shifts. The brilliance and variety make them stand out in the world of precious stones.

To explore our collection, visit the opal gemstones page.

Opal Colors

Pinpointing an opal's color isn't straightforward - it's like trying to describe an abstract painting splashed with vibrant hues from the entire rainbow.

Opals fall into two main categories: precious and common. Precious opals showcase the famous play-of-color, while common ones don't. For now, let's focus on precious opals.

These are subdivided into types like white opals (the most widespread), black opals (with colors against a dark backdrop), and fire opals (solid bright yellows, oranges, or reds).

The background color comes from impurities in the silica, much like other gems. But the play-of-color? That's from millions of tiny silica spheres stacked irregularly, diffracting light into a spectacular display.

With so many colors possible - even multiple on one stone - figuring out the rarest or most valuable can be tough.

Red tends to top the list as the rarest and priciest, since it requires larger spheres, which are scarcer. Rarity follows the spectrum: reds and oranges command higher values, while greens and blues are more common.

Pair a rare red with a black background, and you've got a top-tier gem. Of course, color density and patterns factor in too.

Some mines even assemble weekly committees of experts to appraise opals. They price individually, then average it out - highlighting just how subjective opal valuation can be.

Opal Patterns

Beyond colors, opals feature distinct patterns. No two are identical, but certain arrangements stand out and fetch admiration.

The harlequin pattern reigns supreme: large, uniform color patches resembling a mosaic or checkerboard. True harlequins are exceptionally rare and prized.

Other patterns worth noting include:

Flagstone

Large color sections with random straight edges.

Straw

Thin, overlapping color ribbons.

Chinese Writing

Strips resembling Chinese characters.

Pinfire

Tiny color dots or flecks.

Floral

Flowery designs.

Broad Flash

Large flashing color sections as the stone moves.

Opal Varieties

As noted, opals split into common and precious types, with precious further categorized. Naming varieties can get complex - with over 20 natural kinds, plus shapes influencing labels - but we'll stick to key ones.

Black or dark opals are rarest and most valuable, with a dark base tone highlighting vibrant colors. Australia dominates production, though Ethiopia contributes some.

For in-depth knowledge, read our black opal gemstone information and education.

White or light opals are more common but still stunning, with milky or transparent bodies and impressive play-of-color.

Fire opals glow in yellows, oranges, or reds, often without play-of-color. If they do show it deep inside, they're precious fire or jelly opals - quite rare. Mexico leads, with Australia following.

Explore further with our fire opal detailed information.

Find out about the opals from fiery desert origins.

Boulder opals retain their host rock, adding to the appeal, especially with dark matrices.

Delve into boulder opal comprehensive guide.

Matrix opals embed opal flecks in rocks like sandstone, polished to reveal colorful specks.

Others include Koroit opals, Yowah nuts, dendritic opals, opalized wood, and hyalite. Some bear origin names like Peruvian or Tanzanian opals, or colors like pink or blue.

Discover moss opal variety details, chocolate opal gemstone information and education, and hyalite opal specific information.

Synthetics match opal's chemistry, imitations use plastic, and composites like doublets (opal on backing) or triplets (with protective dome) exist. As long as disclosed, they're fine.

Learn about the fascinating cat's eye opal phenomenon and info.

Opal Clarity

Clarity measures transparency and internal flaws; generally, clearer gems are pricier. Opals bend the rules a bit - they're unique.

They're rated as transparent, translucent, or opaque. For black opals, an opaque dark base enhances colors, while crystal opals need high clarity to reveal depths. Milkiness dulling play-of-color lowers value.

In boulder or matrix opals, the rock integration makes clarity less critical - what makes them distinctive and attractive.

Opals hold surprising moisture - up to 20% in some cases!

Exposure to sun or dryness can cause evaporation, leading to "crazing" cracks. Treatments may fix this.

What Does an Opal Symbolize?

Disclaimer: The spiritual properties discussed here stem from traditional folklore and metaphysical beliefs. They lack scientific backing and aren't substitutes for professional advice.

Opals evoke passion, linked to desire, seduction, and freeing inhibitions while inspiring love. They aid in attracting partners, boosting appeal, and nurturing relationships.

Color dictates spiritual influence, and with rainbow hues, opals affect broadly.

Chakras are body energy centers, each tied to a color: crown (purple), third eye (indigo), throat (blue), heart (green), solar plexus (yellow), sacral (orange), root (red).

An opal's dominant color aligns with a specific chakra.

Varieties vary: fire opals ignite creativity and drive change; milky opals soothe and clear minds, ideal for calm environments.

Overall, opals surface emotions, build self-belief, unlock potential, spark originality, and foster arts interest. They embody karma - balance and the idea that actions return.

Gain more understanding of opal symbolic meaning, powers, and practical uses.

Opal Health Benefits

Disclaimer: The healing benefits described are rooted in historical and cultural traditions. They aren't proven by modern science and shouldn't replace medical treatment. Consult a healthcare provider for health issues.

Opal Prices

Valuing opals is challenging, as we've touched on. Let's break down the key factors.

Color leads: black, boulder, and fire opals with red dominance are premium. Viewing angle matters - vibrant from all sides boosts price.

Play-of-color is crucial: assess coverage, intensity, range, and dominance. Even distribution trumps a single bright spot.

Patterns like harlequin (repeating shapes, especially red) add value, as do bamboo leaf or floral.

Darker base tones elevate black/boulder opals; brighter colors overall help.

Shape: cabochons (oval, domed) are standard; freeforms shine in boulder types. Faceting is rare but suits transparent fire opals.

Inclusions: avoid cracks; clarity enhances play-of-color, though unique ones can intrigue in freeforms.

Source: Australia and Ethiopia lead, but judge the stone itself. Size: larger equals pricier, but don't trade quality for carats.

Opal History

In 1939, anthropologist Louis Leakey unearthed opal artifacts in Kenyan caves dating to 4000 BC - proof humans crafted opal jewelry over 6,000 years ago.

"Opal" derives from Sanskrit "upala" (precious stone), via Greek and Latin terms.

Early sources were Ethiopia, Eastern Europe, and Turkey. Rarity persisted until 1800s discoveries in Mexico and Australia. Today, Australia supplies 95% of precious opals.

Where Is Opal Found?

Opals appear in Mexico, Brazil, Honduras, the US, and Ethiopia, but Australia mines the majority.

Australia produces 90-95% worldwide, starting with common opal in 1849. Precious finds in the late 1800s/early 1900s boosted the industry.

Key sites: Mintabie, Coober Pedy, Andamooka (South Australia); White Cliffs, Lightning Ridge (New South Wales); Winton, Quilpie (Queensland). Mining in harsh outback conditions is demanding.

About 100 million years ago, a shallow sea covered central Australia, seeding opal formation along its ancient shores: boulder north, black east, white south.

How Is Opal Formed?

Debate persists on opal formation, given diverse varieties. The leading theory: water infiltrates rock cracks, evaporates, leaving silica gel that hardens over millions of years into opal types.

Can Opals Be Treated?

All gems get cut and polished, but additional treatments like heating or dyeing vary. Disclosure is key.

Typically, opals receive only basic cutting and polishing.

To darken for black-like effect: smoking infuses particles, or acid/sugar cooking produces carbon.

Composites like doublets/triplets involve assembly, beyond simple shaping.

Heating doesn't alter opals much. Despite high water content, they're less prone to damage from sun or dryness than rumored.

What Jewelry Is Opal Suitable For?

At 5.5-6.5 Mohs hardness - like glass - opals need mindful use to avoid scratches.

Opals make striking engagement rings beyond diamonds. Opt for low-dome cabochons, bezel settings, or durable boulder types.

For less-worn pieces like pendants, earrings, or necklaces, opals excel with less risk.

Metals pair based on taste, matching opal's colors.

Large black, boulder, or matrix opals suit bold, handmade items in unique shapes.

Did You Know? Unusual Facts About Opal

• Opals are October's birthstone.

  Perfect gift for October birthdays - with endless styles, one will fit.

• Coober Pedy's name? From Aboriginal "kupa piti" - "white man in a hole!"

  Refers to miners or settlers escaping heat in dugouts. Named in 1920s.

• Half of Coober Pedy residents still live underground for coolness.
• Lightning Ridge? Named after a 1870s strike killing a farmer, dog, and 200 sheep.

  Now, it's the black opal hub.

• Opals mark 14th wedding anniversaries.
• Opals on Mars? Conditions mirror Australian deserts.
• A book nearly tanked opals.

  Walter Scott's 1829 "Anne of Geierstein" blamed an opal for tragedy, crashing sales for decades.

• Queen Victoria revived demand with opal gifts and wear.
• Rarest combo? Red and blue.

  Opposite spectrum ends make it near-impossible.

• Some opals are double-sided with differing colors.
• Coober Pedy starred in "Mad Max Beyond Thunderdome."
• Opal rarity?

  95% mined is worthless potch; of the rest, most is low-grade. Only 0.25% holds value.

How to Care for Opals

Soft at 5.5-6 hardness, opals withstand minor impacts but deserve protection. Remove jewelry for cleaning, sports, or gardening.

Solids tolerate water but not dryness or temp swings. Store with damp cloth in dry spots like safes; avoid prolonged sun or dehumidifiers.

Doublets/triplets: Skip long soaks to protect glue/backing.

Store separately in cloth bags to prevent scratches.

Avoid ultrasonics (fractures/loosening) and steam (heat sensitivity). Clean with soft cloth, mild soap if needed.

For additional advice, consult our detailed caring for opals guide.

How Do You Know If You Have a Real Opal?

Buy certified from trusted dealers, but when hunting bargains, verify.

Opal's structure challenges fakes, but synthetics (1974), glass/foil, opalite (plastic), and grown opals exist.

For doublets/triplets: White/transparent unlikely with black backing. Side view shows layers; back check: plastic = triplet, flat join = glued, bumpy = natural.

Triplets look glassy atop; translucency from side signals one.

Synthetics: Patterns too perfect, no gaps, orderly repeats.

Price flags: Too cheap for quality? Likely fake.

Not exhaustive, but helpful. GemSelect offers reports from AIGS or BGL Lab.

What Is So Special About an Opal?

One opal can hold a rainbow - unique enough? Its amorphous structure allows odd shapes. Spheres diffract light for color play. Formed by ancient rain seeping and hardening over eons - that's remarkable!

Can Opal Change Color?

Opals shift with angles, not light sources like alexandrite or color-change garnets.

Under fluorescents, play-of-color may dull due to incomplete spectrum.

How Can You Tell a Good Quality Opal?

Quality varies by taste, but from reputable sources, check type (black/white/crystal), play-of-color (intensity/coverage/color/pattern), transparency (no cracks/cloudiness), and cut (symmetry/polish).

Ultimately, if it resonates - feels right in hand, exudes energy - it's yours.

Opal - Gemological Properties

Frequently Asked Questions