How to Care for Opals: The Essential Guide

TL;DR: Mastering how to care for opals ensures their brilliant fire and play of color endure for generations. This practical guide breaks down what makes opals geologically distinct, everyday wear habits, safe cleaning protocols, and essential storage advice. Learn why ultrasonic cleaners must be avoided, how to clean opals safely using mild soapy water, and when to bring your jewelry in for a professional checkup.

Few gemstones capture the imagination quite like an opal. Flashing with kaleidoscopic fire, every stone holds its own tiny cosmos. But if you have ever found yourself staring down at a rainbow-hued treasure wondering how to keep that luminous dance alive, you are not alone. Knowing how to care for opals is the secret to enjoying their mesmerizing color play for generations, without stress or guesswork.

What Makes Opals Different from Other Gemstones?

Most gemstones you encounter in fine jewelry, such as diamonds or sapphires, are crystalline structures formed under tremendous heat and pressure. Opals take a completely different geological path. They are amorphous hydrated silica, which means they do not have a rigid crystal lattice. Instead, tiny sub-microscopic spheres of silica align in layers, diffracting white light into a breathtaking prism of color.

There are three important gem types that the ancients correctly considered amorphous: natural glass (moldavite and obsidian, among others), amber, and…opal. Opal is truly non-crystalline. It has no predictable internal structure.

In addition to those structural features, another characteristic of opal that is unique in the gem world is its actual chemical composition: SiO₂·nH₂O Hmmmm, do you recognize something in there? Yep, H₂O–-water! SiO₂ is silica. (The “n” is indicating that the quantity of water can vary between 3% and 21%, with most gem-grade varieties containing 5% to 10%.) So opal is actually a hydrated form of silica.

On the Mohs hardness scale, they rate between 5.5 and 6.5. This makes them easier to scratch than quartz, emeralds, or corundum; but more difficult to scratch than a pearl. Think of them less like armor and more like silk: exquisitely crafted, totally wearable, but deserving of a little common sense and conscious love.

Everyday Wear: Smart Habits for Opal Jewelry

Can you wear your opal jewelry frequently? Absolutely. Do you need to adjust your habits so you do not accidentally test geological limits? Definitely. Following simple precautions keeps your gemstone shining brightly.

• Apply the last on, first off rule: Always put your opal pendants, earrings, and rings on after your hairspray, perfume, makeup, and lotions have completely dried. Chemical compounds in cosmetics can slowly dull the stone's polished surface over time.
• Remove during physical labor: Take off your opals before lifting weights, weeding the garden, deep cleaning the kitchen, or moving furniture. A sharp blow against a hard surface like granite or cast iron can crack or chip a softer gem.
• Mind the style: Opal earrings and pendants naturally live safer lives than rings, as they do not knock against door knobs or desks. If you adore an everyday opal ring, look for protective settings such as smooth bezels or low-profile designs that shield the edges of the stone.

How to Care for Opals with Safe, Simple Cleaning

When it comes to cleaning opals, simpler is always better. You do not need fancy proprietary chemical dips or high-tech equipment. In fact, chemicals and cleaning devices are the quickest route to heartache.

• Never use ultrasonic or steam cleaners: The intense micro-vibrations of an ultrasonic cleaner can shatter internal structures, while hot steam can shock the water balance inside the gem.
• Stick to mild soapy water: Swish your piece gently in a bowl of lukewarm water mixed with a drop of mild, additive-free dish soap.
• Use a very soft cosmetic brush: If dirt has settled behind the setting, gently coax it away using a clean, very soft cosmetic brush. Never scrub aggressively.
• Pat dry immediately: Rinse with clean, lukewarm water and gently blot with a soft, lint-free cloth. Allow the piece to air dry completely before storing it away.

How to Care for Your Opal if it’s a Boulder, Nut, or Matrix Opal

In the case of boulder, nut, and matrix opals, the opal layer is stabilized through the host rock being left intact. So, there’s no cement to concern yourself with. If possible, treat these opals as you would solid opals: by storing such opals and jewelry made with them in distilled water.

Cleaning Opal Jewelry with Boulder, Nut, or Matrix Opal

Boulder, nut, and matrix opals may be cleaned using the same opal cleaning cycle as solid opals: in warm water and super-mild detergent with a soft cloth. Keep away from household cleaners like bleach and other chemicals. Be sure to rinse off under running water any detergent you do use, and dab dry with a tissue.

How to Care for Your Opal if it’s an Assembled Opal

In addition to possessing a delicate and thin layer of opal material, opal doublets and triplets also have the additional layer or layers of material affixed to the opal layer. The non-opal materials are never as delicate as the opal itself, so that does not present an additional concern to a solid opal.

But, the cement or glue itself is something that can make caring for an assembled opal a little trickier. There is such a tiny amount of cement used in assembling a doublet or triplet, that just minor effects on it can cause the adhesive to release. So, unfortunately, one should not store an opal doublet or triplet in distilled water. The stability that is gained in having a man-assembled opal means you can’t use the distilled water trick to keep the opal layer hydrated.

How to Safely Clean Opal Jewelry with Opal Doublets or Opal Triplets

It is OK to use a moist towel and mild detergent to clean doublets or triplets, but they should never be submerged or soaked.Be sure to rinse off under running water any detergent you do use, and dab dry with a tissue.

Opals should not be cleaned using standard jewelry cleaner used for diamonds and other non-porous gems.

Moisture, Temperature, and Storage Considerations

Because opals contain trapped water, sudden environmental changes can cause issues. Rapid swings from warm room temperatures to freezing conditions, or exposure to bone-dry heat sources, can lead to crazing (fine web-like surface cracking). Here is how to keep your solid opal stable and comfortable:

• Avoid extreme thermal shock: Do not wear your opal into a scalding hot tub, a sauna, or while reaching into an oven, and keep it sheltered from sub-zero winter chills.
• Moisture if possible (for solid opal only): Since water is part of opal’s chemical composition, an ideal situation for opal is to be stored in a container of distilled water. Not tap water, not spring water, not any other kind of water. Distilled water only. Caring for your opals in this manner keeps the water that is already present in the opals, in the opals. [FUN FACT: certain kinds of water opal (most notably Ethiopian hydrophane opal) soak up water readily, and some of them go almost colorless in the process. They also lose the water they soak up in a matter of a couple weeks, and then their color returns. Storing them in water is fine for them, but impractical because of how they change in look.]
• The happy middle ground (good for all opals, including doublets, triplets, boulder, or nut opals): Care for your opal jewelry by storing in a normal ambient room environment. If you live in an exceptionally dry climate or use a dehumidified vault, simply keeping an unsealed small dish of water nearby provides ambient humidity.
• Avoid the myths: You may have read folklore suggesting opals should be soaked in mineral oil or glycerin. Do not soak solid natural opals in oils or glycerin; foreign oils can penetrate microscopic crevices and discolour the stone.

Quick Checklist: Daily Opal Care

• Put on after cosmetics, lotions, and sprays.
• Remove prior to sports, chores, and swimming.
• Clean only with warm water, mild soap, and a soft cloth.
• Keep far away from ultrasonic tanks and steam machines.
• Store individually in soft pouches to avoid scratches.
• Shield from sudden temperature spikes and prolonged dry heat.

When to Consult an Expert Jeweler

Even with attentive care, rings experience normal wear over the years. Settings loosen, metals wear down, and stones can gather tiny surface scuffs. Periodic inspection ensures your setting remains secure and the gemstone stays firmly seated.

If your opal has lost a bit of its surface polish after years of faithful wear, do not attempt to polish it at home with abrasive compounds. A skilled jewelry professional can safely inspect the mountings, check prong integrity, and assess whether professional polishing can safely revive that original mirror luster.

Frequently Asked Questions

Can opals get wet?
Solid natural opals are fine with incidental exposure to water, such as washing your hands or walking in gentle rain. However, remove them before swimming in chlorinated pools or bathing, as pool chemicals, salt water, chlorine, and harsh detergents can damage the stone and/or mounting over time.

What is the difference between solid opals and assembled stones?
Solid opals consist entirely of natural gem material. Doublets and triplets, however, are layered gemstones where a thin slice of opal is glued to a dark backing (and topped with clear quartz or glass in the case of triplets). Assembled stones should never be submerged in water, as moisture can dissolve or cloud the adhesive layer. Clean doublets and triplets exclusively with a damp cloth.

Why did my opal look cloudy after cleaning?
If you used a chemical dip or left a porous variety soaking in tap water, it may have temporarily absorbed liquid or residue. Let it air dry slowly at room temperature away from direct sunlight or heat. Avoid foreign polishes and household chemicals entirely.

For a deeper technical dive on opal quality and durability, the Gemological Institute of America's opal buying guide is an excellent outside resource.

Celebrate the Magic in Your Collection

Caring for fine jewelry should feel joyful, not intimidating. Opals bring unmatched character, organic fire, and natural artistry into your daily life. With a tiny bit of mindful attention, your treasured pieces will keep glowing for decades to come.

Have questions about an opal in your jewelry box, or want an expert eye to check your settings? Explore our educational resources, stop by our showroom, or book a friendly consultation with our team at Alara Jewelry. We are always here to help you enjoy every piece you wear.

Written by Babs Noelle, Founder and Graduate Gemologist (GG) of Alara Jewelry, Bozeman, Montana.