Aquamarine carries the colour of the sea in its name and in its heart. Its serene sky-to-sea blue feels entirely at home in the Caribbean, and unlike many coloured gems it is usually wonderfully clear and available in large, clean sizes. For a stone of such presence it is also refreshingly practical to wear. This guide explains what aquamarine is, what to look for in colour and clarity, and how to choose a piece that will last a lifetime, and you can see fine examples across our coloured gemstone collection.
In short: with aquamarine, depth of colour is the great differentiator, so prioritise a pure, saturated blue over a pale or greenish one, expect the stone to be eye-clean, and enjoy that at 7.5 to 8 on the Mohs scale it wears well every day. Most aquamarine is routinely and permanently heated to a purer blue. Aquamarine is March's birthstone, and bought in George Town it is entirely tax-free.
Aquamarine at a Glance
Here are the facts clients ask for most often, gathered in one place and expanded in the sections that follow.
| Property | Aquamarine |
|---|---|
| Mineral | Beryl (beryllium aluminium silicate) |
| Colour range | Pale sky blue to deep sea blue, sometimes greenish |
| Mohs hardness | 7.5 to 8, with good toughness |
| Notable sources | Brazil, Mozambique, Nigeria, Madagascar, Pakistan |
| Birthstone | March |
| Anniversary | Nineteenth wedding anniversary |
| Common treatment | Heat, to remove green or yellow tones |
| Care | Warm soapy water and a soft brush; durable for daily wear |
The Blue Beryl
One family, three colours
Aquamarine is the blue to greenish-blue variety of beryl, the same mineral family that gives us green emerald and pink morganite. Its colour comes from traces of iron, and the name derives from the Latin for sea water. Where emerald is the deep green member of the family, aquamarine is the cool blue one.
Why it grows so clean
The two beryls could hardly behave more differently in the ground: emerald grows full of fractures and inclusions, while aquamarine often forms large, remarkably clean crystals. That single fact shapes almost everything about how the stone is judged and worn, from the high expectation of clarity to the ready availability of big, transparent stones.
Colour, Clarity and the Santa Maria Ideal
Colour, the great differentiator
Aquamarine ranges from the palest sky blue through to a deeper sea blue, sometimes with a green cast. The most prized colour is a pure, moderately saturated blue with little or no green, the look made famous by the legendary Santa Maria mine in Brazil and later echoed by fine Santa Maria Africana material from Mozambique. Because much aquamarine is naturally light, depth of colour is what commands a premium.
Clarity, where eye-clean is the rule
Clarity is usually excellent: most fine aquamarine is eye-clean, and visible inclusions are far less acceptable than they are in emerald. This combination of clean crystal and cool colour is why aquamarine is one of the few coloured gems regularly cut into large, flawless-looking statement stones.
| Colour | Description | Relative value |
|---|---|---|
| Pale sky blue | Light, delicate blue; very common | Entry level |
| Medium blue | Clear, lively blue with good saturation | Mid range |
| Deep sea blue (Santa Maria) | Pure, richly saturated blue with little green | Most prized |
What Drives the Value
Four factors decide the price of an aquamarine, and they do not carry equal weight. Colour leads by a wide margin, followed by clarity, then cut and finally carat. Because clean material is relatively plentiful, you can hold out for the colour you love without sacrificing size, which is rarely the case with scarcer coloured gems.
- Colour, the leading factor. A pure, saturated blue is most desirable; pale or strongly greenish stones are more common and less valuable.
- Clarity, where eye-clean is the expectation. Aquamarine should look transparent and bright, with no eye-visible inclusions in fine material.
- Cut, which brings out the blue and the brilliance. Well-proportioned emerald cuts, ovals and cushions show the colour beautifully across larger stones.
- Carat, since clean rough is plentiful, so larger sizes are attainable, though deeply coloured large stones remain the most sought after.
Origin and Treatment
Where aquamarine is found
Fine aquamarine is mined across several continents, with Brazil's Minas Gerais the historic heartland, alongside important sources in Mozambique, Nigeria, Madagascar, Zambia and Pakistan. Our guide to coloured gemstone jewellery in Cayman explains how we weigh origin against the colour and clarity you can actually see.
Heat treatment
Most aquamarine on the market is routinely heated to remove a yellow or green component and settle the stone into a purer blue. This treatment is gentle, undetectable and permanent, it is accepted throughout the trade, and the resulting colour is stable in normal wear. As always, a trustworthy jeweller discloses treatment plainly rather than implying that ordinary heated material is something rarer.
Durability, Birthstone and Settings
Built for everyday wear
Aquamarine measures 7.5 to 8 on the Mohs scale with good toughness and no troublesome cleavage, which makes it well suited to everyday wear, including rings, with sensible care. Its clean clarity makes it a natural choice for large cocktail rings, pendants and statement earrings, and it makes a serene, unconventional centre for coloured-stone engagement rings.
The March birthstone
Aquamarine is the birthstone for March and the gem of the nineteenth wedding anniversary, long linked with calm, clarity and the sea. It pairs especially well with cool white metals; platinum and white gold sharpen its blue, and a halo or accent of diamonds adds sparkle around the calm colour, while the choice of metal is covered in our precious metals guide. See where it sits among the other birthstones by month, and find ideas in our anniversary jewellery gift guide.
Care
Clean aquamarine with warm soapy water and a soft brush; ultrasonic cleaners are generally safe for inclusion-free stones, though gentle hand cleaning is the safest habit, and prolonged strong light or heat is best avoided. Our guide to cleaning and caring for fine jewellery sets out a safe routine in full.
With aquamarine, depth of colour is the prize: choose the purest, most saturated blue your eye can find, enjoy its natural clarity, and wear it knowing it is tough enough for everyday life.
Buying Aquamarine Tax-Free in Grand Cayman
Whether you are drawn to a delicate sky blue or a deep sea blue, our team will help you weigh colour, clarity and cut and find a stone that suits your hand and your wardrobe, alongside our wider fine jewellery. Worn against Caribbean light, a fine aquamarine seems to hold the colour of the sea itself.
Walk in whenever it suits you, with no appointment needed. Every purchase is tax-free, with no sales tax and no VAT, so an aquamarine here can cost roughly 20 to 35 percent less than the same stone in the United States, the United Kingdom or Europe, and we offer free insured worldwide shipping. See how tax-free shopping works, or visit us on the George Town waterfront.