Gemstones & cuts
Aquamarine, and the case for a big stone
Emerald's clean-living cousin: big, bright and surprisingly affordable.
Written by our in-house jewelry team · Updated August 1, 2026 · 5 min read
In short
Aquamarine is the blue variety of beryl, the same mineral family as emerald, at 7.5 to 8 on the Mohs scale but far cleaner and tougher because it lacks emerald's dense inclusions. Heat treatment to remove a greenish tone is routine and stable. It gives real presence on the hand for a fraction of the cost of comparable sapphire.
Aquamarine is the stone of Retro and mid-century cocktail rings, precisely because it comes out of the ground in large, clean crystals.
Shop the pieces: Aquamarine, curated and available now.
The essentials
The blue side of beryl, typically clean, typically available in sizes that would be unthinkable in sapphire.
Species and group: Beryl (beryllium aluminum silicate). Mohs hardness: 7.5 to 8. Typical colors: Pale sky blue to deeper blue, sometimes with a green secondary tone.
- Usually eye-clean, unlike emerald, and available in large sizes
- Distinctly dichroic: color can look stronger down the length of the stone
- Commonly cut as emerald cuts and elongated step cuts to show the color
- Hardness suits daily wear, though the stone can chip at sharp corners
Heat, and the green you no longer see
Most aquamarine leaves the ground with a green cast and is heated to remove it. In older jewelry you sometimes meet the untreated green-blue original, which is worth recognizing.
Our gemologist examines every stone before a piece is listed, and the description states what is known and what cannot be determined without a laboratory report.
- Heat treatment to remove a yellow-green component: routine, stable and accepted
- Irradiation is used on some beryls but is uncommon for aquamarine
- Blue synthetic spinel and blue topaz are frequently mistaken for or sold as aquamarine
- Glass imitations appear in costume jewelry and are identified by bubbles and warmth to the touch
Judging color and clarity
With aquamarine, tone does almost all the work. A large pale stone and a smaller saturated one are not competing for the same buyer.
- Aquamarine's blue is typically softer and greyer than the electric blue of treated topaz
- Turn the stone: aquamarine's dichroism produces a visible change in depth of color
- Blue glass shows swirls or bubbles and feels warm quickly in the hand
- Natural stones often show fine liquid or hollow tube inclusions
Deco geometry and Retro scale
Aquamarine became a signature of the Retro period from the late 1930s, cut into big rectangular steps and set in rose or yellow gold, then continued into mid-century cocktail rings.
Edwardian jewelers used smaller stones with platinum and diamonds, where the pale blue reads almost as a colorless accent.
Frequently asked questions
- Is aquamarine the same as blue topaz?
- No, they are different minerals. Blue topaz is usually irradiated to a stronger blue and is generally less expensive.
- Why is my aquamarine so pale?
- Deeper blue is rarer and priced accordingly. Larger stones can look more saturated simply because there is more material for light to travel through.
- Can I wear an aquamarine ring every day?
- Yes, with a setting that protects the corners. Avoid knocks against hard surfaces, as with any step-cut stone.
Written by our estate jewelry team and reviewed by our in-house gemologist. We have been buying and selling European antique jewelry since 1973.
From the reading to the piece
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Each piece is one of a kind and sells once, so this collection changes constantly.
View aquamarineRelated guides
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