What Aquamarine Actually Is

Aquamarine is beryl, the same mineral family as emerald. Iron gives it the blue; chromium or vanadium would have made it green and called it emerald instead.

That family resemblance matters commercially. Emerald is typically full of inclusions and fragile. Aquamarine grows in large, clean crystals, which is why a clean aquamarine of a few carats is affordable while a clean emerald of the same size is not.

The name comes from the Latin aqua marina, sea water. Roman sailors carried it for safe passage, and the stone has been tied to calm water and clear communication ever since.

The Color Rule Nobody Tells You

Most aquamarine is pale. Deeply saturated blue is genuinely rare and priced accordingly. But there is a second factor that catches buyers out, and it has nothing to do with quality.

This inverts the usual advice. With most gems you can buy a smaller stone of better quality and keep the look. With aquamarine, going too small loses you the color you were paying for. If the blue matters to you, put the budget into size before you put it into grade.

Almost All of It Is Heat Treated

Aquamarine commonly comes out of the ground with green or yellow tones. Gentle heating removes them and leaves a cleaner blue. The change is stable and permanent, needs no special care, and is accepted throughout the trade.

It should still be disclosed. Under the FTC Jewelry Guides, treatment must be disclosed where it is not permanent, requires special care, or significantly affects value. A seller who cannot tell you whether a stone is heated either does not know their supply chain or is choosing not to say.

Durable Enough for a Ring, Which Is Unusual

At 7.5 to 8 on the Mohs scale, aquamarine is harder than garnet, amethyst, opal, pearl and turquoise. Among the colored birthstones it sits just behind ruby and sapphire.

Practically, that means aquamarine is one of the few birthstones you can reasonably set as the center stone of a ring worn every day. It has no cleavage plane that makes it liable to split, though like any gem it will chip if struck hard on an exposed corner.

• Rings: fine for daily wear. Protect corners on emerald-cut stones with a bezel or corner prongs.
• Necklaces and earrings: ideal, and the easiest way to wear a larger stone where the color reads best.
• Heat and chemicals: avoid steam cleaners, ultrasonic machines if the stone has visible inclusions, and household chemicals.
• Storage: store separately. A diamond will scratch it, as will sapphire and ruby.

What Gets Sold as Aquamarine but Is Not

This is where cheap March jewelry goes wrong. Three substitutes turn up constantly.

Choosing Aquamarine Jewelry

1. Decide whether color or size matters more, then remember they are the same decision with this stone. A larger, paler stone usually reads bluer than a small, better one.
2. Check it is eye-clean. Aquamarine commonly grows clean, so visible inclusions are a reason to compare other stones rather than accept it.
3. Look at the cut. A well-cut aquamarine looks lively; a poorly cut one looks like pale glass. Emerald and step cuts suit the material and show color evenly.
4. Choose the metal against the color. White gold and platinum keep the blue cool and clean. Yellow gold warms it and can make a pale stone look slightly green.
5. Consider diamond accents. A lab-grown diamond or moissanite surround adds the sparkle a pale stone lacks on its own, without a large jump in price.
6. Get it in writing. Mineral name, natural or lab-grown, treated or untreated, and the metal karat.

Caring for It

• Clean with warm water, mild soap and a soft brush. Dry with a soft cloth.
• Avoid ultrasonic and steam cleaning if the stone has any visible inclusions or fractures.
• Keep it away from prolonged strong heat, which can alter the color of some stones.
• Store it apart from diamonds, sapphires and rubies, which will scratch it.
• Have the setting checked periodically, particularly on a ring.

Frequently Asked Questions