Mother of pearl, abalone, and paua adorn some of my favorite pieces that leave this studio: necklaces, rings, earrings, bolo ties. Sometimes as a broad inlay and sometimes as a crushed-shell face. They look different from one another, but they are all made of the same material. That material is nacre, and care follows from how nacre is built.
What is Nacre?
Nacre is a layered composite. Think of it like a brick wall. Thin plates of calcium carbonate, called aragonite, stack like bricks. Thin films of an organic material called conchiolin act as the mortar between them. That architecture shows up in both pearls and the polished inner surfaces of pearl-producing shells, including abalone. Pearl and mother of pearl are the same nacre in different geometries: a pearl deposits it around a center, while mother of pearl is the nacreous lining of the shell.
Abalone brings that colorful lining into jewelry. Paua is New Zealand abalone (Haliotis iris), worked from the same kind of inner nacreous layer. Mother of pearl covers the quieter whites, blacks, browns, and golds from other shells. None of those names needs its own care routine. The surface that shows is nacre either way.
Soft to Scratch, Harder to Crack
The Throne (Gold Mother of Pearl & Continuum Silver Two Finger Ring)
On the Mohs hardness scale, pearl nacre ranks about 2.5. That number is a scratch ranking: it says how easily one mineral surface marks another. A fingernail sits near the same range. Almost every other gemstone is capable of scratching nacre. That is why these pieces want their own soft pouch instead of sharing a drawer with metal and harder stones.
Scratch resistance isn't the whole story, though. The platelet-and-organic stack gives nacre far more resistance to cracking than bulk aragonite has on its own. Hydrated nacre fails by tablets sliding and cracks deflecting at the organic interfaces rather than splitting cleanly like a single crystal. Dry nacre loses that sliding behavior and fails more like the plain mineral, which is one reason high heat and dry-hot storage are hard on it.
So the layered structure is a caveat on the Mohs number, not a promise. A thin inlay or a crushed-shell face can still crack from a hard knock, and the surface still scratches as easily as a 2.5 implies. On a piece meant for daily contact, I treat the nacre as soft.
Why the Look Dims When the Surface Changes
The color that moves across abalone and mother of pearl isn't a pigment sitting on top. It's structural color: interference and diffraction in the closely packed aragonite layers. The light bounces around inside before reflecting back out at different angles. That gives it the characteristic rainbow effect. Gemologists call the iridescent play in nacre "orient," and it depends on an intact, smooth layered surface.
Acid etching and fine abrasion roughen that geometry. Light that used to reflect in organized layers starts to scatter instead, and the surface goes dull, chalky, or hazy. That change doesn't age into character the way wood sheen or copper color does in patina. Nacre looks best when it is pristine and protected.
Chemicals, Perspiration, and Heat
Ebony Wood & Crushed Mother Of Pearl Ring
Aragonite is made of calcium carbonate mineral, and calcium carbonate reacts with acid. That is the ordinary chemistry behind why many household chemicals, and everyday perspiration are hard on a nacre surface. Perfume, hairspray, and cosmetics land in the same group: not because a single mist ruins the shell, but because residue left on it can dull or etch the optical surface over time.
On the mother of pearl, abalone, and paua I set into wood and metal, that means putting the piece on after fragrance and cosmetics, then wiping the shell gently once it comes off. A ring sees more skin contact than earrings do, so it earns that wipe more often. A small GIA study of limited perfume, hairspray, and cream exposures found no visible change in its tested pearls. What matters is not letting those residues sit on the shell.
Crushed Abalone & Ebony Wood Bolo
Chlorine is especially hard on pearl nacre, so pool and hot-tub water are out for a piece that carries it. Ultrasonic and steam cleaners don't belong on pearls or shell cameos, and they don't belong on a mixed wood-and-shell piece either. High heat can discolor, split, or crack nacre. Ordinary indoor daylight is fine; the warnings about intense light are really warnings about heat.
Ocean swimming runs into a limit the wood already set. Water is a duration question for a finished wooden piece, covered in the complete guide to wooden jewelry care. Salt water doesn't add a separate etching problem for nacre on top of that.
Cleaning and Touch-Up on a Mixed Piece
The Lasso (Gold Mother Of Pearl, Ebony Wood & Sterlium Plus Silver Bolo Tie)
A soft, clean, dry cloth is the everyday wipe I use on a finished piece that includes nacre, with extra attention to the shell where skin has touched it. Occasional warm soapy water is safe for pearls on their own, but on a piece that also carries finished wood, metal, and sometimes leather or stone, pearl-safe doesn't mean the whole object can take a soak. If a dry wipe isn't enough, the next step is a cloth wrung nearly dry, not a rinse. Anything beyond surface cleaning is a reason to bring the piece back in.
Mineral oil is the at-home touch-up for the wooden surface, the same refresh I recommend in What Oil Should You Use on Wooden Jewelry?. It stays on the wood and off the shell. Oil and wax coatings don't belong on nacre either.
Crushed shell and solid inlay get the same cloth and the same chemistry: same material, different shape.
Storage That Respects a Soft Surface
Anything harder will scratch anything softer. Nacre at about 2.5 will pick up marks from metal, harder stones, and grit if pieces share a loose drawer. A soft pouch or a lined compartment keeps that contact from ever happening. Sealed plastic bags are a poor home for the same reason dry-hot storage is: both are hard on a nacre surface over time. Silica gel is a poor choice here for the same reason it's wrong for finished wood: it dries the air around the piece instead of leaving it in a stable indoor room.
The fuller storage picture for mixed wooden jewelry is in How to Store Your Wooden Jewelry to Last a Lifetime.
Protection, Not Patina
The Lasso (Paua Select Abalone Shell, Ebony Wood & Sterlium Plus Silver Bolo Tie)
Nacre's look comes from geometry that is already there. Wear that etches, scratches, or chalks the surface isn't the equivalent of wood going richer or copper going warm. Lifetime reconditioning comes with every piece that leaves the studio, and it's the right move for finish, fit, and general maintenance. What it can't promise is that etched or scratched nacre comes back to its original orient.
If you're choosing mother of pearl, abalone, or paua for a custom piece, we can talk through how that surface will live next to the wood and metal beside it before the piece is made.
Sources for this post: the GIA (pearl care and cleaning, pearl buyers guide, ultrasonic guidance, travel guidance, and Gems & Gemology research on nacre and iridescent abalone shell), peer-reviewed work on nacre mechanics and structural color, and the Museum of New Zealand Te Papa Tongarewa on pāua.
