Akoya pearls are the classic — round, lustrous, white. But the most desirable Akoya are not white at all. They're white with an overtone — a subtle secondary colour that floats just over the pearl's surface, shifting with the light. The overtone is what separates an ordinary Akoya from a remarkable one.

At Isaac Westman, every Akoya pearl in the collection is selected at the source for its overtone. Here's what to look for.

What an overtone is

When light passes through the layers of nacre that make up a pearl, it refracts. Thicker nacre means stronger overtone. The overtone is a marker of cultivation quality — and a marker of value.

Unlike body colour (which is inherent to the pearl), overtone is partly the work of the cultivation environment and partly the work of selection. We choose pearls where the overtone reads cleanly, without the cloudy edges that come from thin nacre.

The four overtones to know

Rose. A soft pink hue that flatters most skin tones. Romantic without being overt. The most sought-after Akoya overtone, and the rarest at higher grades.

Silver. A cool, crisp sheen that enhances the pearl's whiteness. Quietly modern. Reads cleaner than rose under cool lighting.

Cream. A warm ivory cast. Less common than rose or silver in fine selection, but elegant on warm skin tones and in yellow gold settings.

Green and aquamarine. Rare hints of green or blue-green, typically seen only in higher-grade selections. Beautiful but uncommon.

Why overtone matters for value

Strong, even overtones are evidence of thick nacre — which means the pearl will hold its luster longer and resist surface dulling. When evaluating a strand, look for uniformity across all the pearls. A single weak overtone on an otherwise strong strand is more visible than you'd expect.

A pearl's overtone is also the most personal choice in the selection — it's the part that suits one wearer over another. Rose flatters warm tones; silver flatters cool. Cream finds the middle.

How we source

Our Akoya pearls come from Ago Bay, on the southeastern coast of Japan — the historical heart of Akoya cultivation. The cooler waters there produce slower nacre deposition, which is part of why Akoya from this region hold their luster longer.

Each pearl is selected by hand for surface, size, and overtone. Then finished at our New York atelier — strung on silk, knotted between pearls, with hidden clasps in 14kt gold to match.

Care

Akoya pearls live well on the skin. Apply perfume and lotion first, jewelry last. Wipe gently with a soft cloth after wear. Store flat in a fabric pouch. We restring and inspect as part of our complimentary annual service.

Enchanting. Intriguing. Refined.

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