A cultured pearl is one of the few pieces of jewelry that an animal builds itself. It grows inside a living mollusk, layer by layer, over the years. And yet “AAAA” is not a law of nature but a scale from the trade. What it measures is something you can learn.
Nacre is made of microscopically thin platelets of aragonite, a crystal form of calcium carbonate, held together by a protein called conchiolin. Each platelet is about half a micrometer thick, roughly the wavelength of green light. That is exactly why a pearl does not shine like polished metal but from within: light is reflected by many layers, slightly offset, and the reflections overlap into a soft glow.
The pearls in our Perla collection are genuine cultured freshwater pearls, grown as hearts, stars and crescent moons, about 8 to 10 mm (0.3 to 0.4 in) in size. Each one is drilled in our studio in Germany and threaded onto the chain by hand. The heart, star and moon have no setting, no bail and no knotted thread: the pearl glides directly on the chain. The oval pearl hangs from a head pin with a hand-wrapped loop.
What a pearl is made of
Aragonite is the same material as the shell. Conchiolin holds the platelets together. With a Mohs hardness of 2.5 to 4.5, nacre is softer than almost any gemstone in the Signature collection.
“A pearl doesn’t show its age in rings but in its luster. The more layers, the deeper the light.”
I. How a cultured freshwater pearl grows.
A mussel coats anything that irritates it with nacre. In pearl farming, a nucleus is placed inside it: in freshwater mussels this is often just a piece of mantle tissue, and for shaped pearls it is a nucleus made of shell that sets the shape. The star on our Pearl Star Necklace was made this way: a star-shaped nucleus, coated with nacre year after year until the points were covered soft and round.
The heart and the crescent moon grow on the same principle. That is why no two hearts are alike: the mussel does not stick to the template and lays down a little more here, a little less there. These small variations are exactly what set a grown pearl apart from a pressed mother-of-pearl shape.
II. The four grading criteria.
Luster is the first and most important criterion: how clearly does light reflect on the pearl? High-quality pearls show a sharp reflection, weaker ones a milky haze. Luster comes from thin, even layers, and you can see it with the naked eye when you hold the pearl under a lamp.
Surface means: how many spots, pits and growth rings does the pearl have? Small irregularities are natural and unavoidable in a grown shape. Chalky patches or chips are not. Shape describes how close the pearl comes to the intended form, which for us means: is the heart a heart, and does the star have five clear points?
Nacre thickness is the criterion you cannot see but can feel: thin nacre looks glassy and cracks at the drill hole. Thick nacre holds up for years.
Why nacre glows from within
Light enters the top layers and is partly reflected at every boundary. The many slightly offset reflections create the luster. The thinner and more even the layers, the clearer the reflection.
III. What A, AA, AAA and AAAA mean.
Freshwater, Akoya, South Sea
6 to 9 mm
Akoya · Japan, saltwater
Classic round pearl, always with a nucleus
8 to 10 mm
Freshwater · river mussel
Our pearls: heart, star, moon, grown over a shaped nucleus
9 to 20 mm
South Sea · Australia, saltwater
Large, expensive pearls, long growing time
The three major pearl types differ in mollusk, water and size. Cultured Freshwater pearls grow in river mussels and allow shaped nuclei, which is why they come as hearts, stars and moons.
The letter scale comes from the pearl trade. It is widely used but not standardized: what one dealer calls AAA, another calls AA. Roughly speaking, A has visible spots and little luster, AA has a decent shine with small flaws, AAA has a clear mirror and an almost clean surface, and AAAA is reserved for the few pearls in a harvest that rank at the top in all four criteria.
In the studio, we do not work with letters but with light. Every pearl is turned under the lamp, viewed from the front and from the side. Anything with a milky haze, a hole next to the drill hole or a dull point does not go on the chain. What remains has the kind of luster you can see in a cultured freshwater pearl without knowing the scale.
How to check for yourself: hold the pearl in daylight and look for your reflection. Run your fingernail over the surface: real nacre feels slightly rough, while glass and plastic feel smooth. And look at the drill hole: with thin nacre, you can see the nucleus there.
IV. Numbers that describe a pearl.
Hardness and size compared
The four criteria
1
Luster
Sharp reflection instead of a milky haze
2
Surface
Few pits, no chalky patches
3
Shape
Heart, star and moon clearly recognizable
4
Nacre thickness
No nucleus visible at the drill hole
Why it matters in the studio
Four promises we make about our pearls.
01
Genuine cultured freshwater pearls.
No glass beads, no plastic, no coating. Every pearl is threaded onto the chain by hand in our studio in Germany.
02
Threaded by hand.
The heart, star and moon are drilled through and glide directly on the chain, with no bail and no setting to hide the luster.
03
Water-resistant chain, dry pearl.
925 sterling silver and 14K gold-filled can handle water. Keep the pearl itself away from perfume, lotion and long baths, and caring for the chain stays simple.
04
A birthstone you can touch.
The pearl is the birthstone for June and, by tradition, the symbol of the pearl wedding anniversary after thirty years.
The next time you hold a pearl up to the light, don’t look for letters. Look for your reflection. If it is clear, the mussel did good work, and we chose well.
A pearl is patience you wear around your neck.
Carola
The heart, star and moon come in 925 sterling silver and 14K gold-filled.
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