Every other birthstone guide tells you to look for a clean stone. With emerald, that advice is wrong, and following it will either cost you a fortune or get you something that is not emerald. Emerald is also the most fragile stone on the birthstone list relative to its hardness, and the only one with a treatment that is not permanent.

Inclusions Are Expected, Not a Defect

Emerald grows under conditions that trap minerals, gas and liquid inside the crystal. The trade calls the result jardin, French for garden, because it looks like one under magnification. An eye-clean emerald of any size is genuinely rare and priced accordingly.

So judge an emerald on color first, clarity second. A richly colored stone with visible jardin looks better on a neck than a pale, clean one.

Almost All Emeralds Are Oiled, and Oil Is Not Permanent

This is the single most important thing to know, and it is the part most sellers skip. Because emeralds are fractured, nearly all of them are filled with oil or resin to make surface-reaching fractures less visible. The practice is centuries old, standard, and accepted throughout the trade.

But unlike the heat treatment used on aquamarine or sapphire, filling is not permanent:

• It can dry out or seep over years.
• It can be stripped by ultrasonic cleaning, steam, solvents or heat.
• If removed, the fractures become visible again and the stone looks worse.
• It can be re-oiled by a specialist — a professional job, not a home clean.

Laboratories grade the degree of filling, commonly described as minor, moderate or significant. The more filling a stone needs, the more fractured it was to begin with, and the more its appearance depends on something that can be undone.

Hard, but Not Tough

Emerald is beryl, the same mineral family as aquamarine, and it sits at about the same place on the Mohs scale. In practice the two behave completely differently.

Hardness is resistance to scratching. Toughness is resistance to breaking. Emerald scores well on the first and badly on the second, because its internal fractures give a knock somewhere to travel. A stone can be hard and still chip easily.

Why a Necklace Is the Right Choice for Emerald

This is not a sales line, it follows from the material. A ring takes constant impact: door handles, desks, car doors, washing up. A pendant hangs free, is rarely struck, and sits away from chemicals and knocks. For a stone that chips more easily than its hardness suggests, that difference matters more than it does for any other birthstone.

An emerald necklace also lets you buy a larger stone than you would risk in a ring, and size helps emerald, because color reads better with more material.

If you want an emerald ring anyway, that is a reasonable choice. Just build it correctly:

• A bezel or halo that protects the girdle and corners.
• A lower profile so it catches less.
• Accept that it will need checking, and possibly re-oiling, over the years.
• Take it off for cleaning, gardening, the gym and anything involving chemicals.

Lab-Grown Emerald Is Real Emerald

Lab-grown emerald is beryl with the same chemistry and optical properties as mined emerald, produced by hydrothermal or flux methods. It is a genuine product, not a simulant, and it must be disclosed as lab-grown. For a May birthstone piece it is worth considering:

• It is usually cleaner than natural emerald at the same price.
• It often needs less or no filling, which removes the care problem above.
• It costs far less than a natural stone of comparable appearance.

The trade-off is collectability. A natural emerald with good color holds interest and value in a way lab-grown material does not. For a gift to wear, lab-grown is often the better buy. For an heirloom, natural is the traditional choice.

What Gets Sold as Emerald but Is Not

• Green glass, sometimes with deliberate bubbles added to mimic inclusions.
• Doublets and triplets, where a thin slice of beryl or glass sits on a backing joined with green cement. Look at the stone from the side.
• Dyed beryl or dyed quartz, where color sits in surface fractures rather than through the stone.
• Green CZ, much softer and too uniformly perfect.
• Other green gems sold loosely as “emerald”: tsavorite garnet, green tourmaline, peridot. All legitimate under their own names.

Buying an Emerald Birthstone Necklace: What to Check

1. Color first. Even, saturated green with no gray or brown cast. This is most of the value.
2. Clarity second, and only in terms of whether inclusions reach the surface or sit where they weaken the stone.
3. Degree of treatment, in writing: minor, moderate or significant.
4. Natural or lab-grown, stated plainly.
5. The setting, protecting the corners and girdle.
6. A laboratory report on anything of real value, stating treatment.
7. Metal. Yellow gold warms the green and is traditional. White metals read cooler. Lab-grown diamond accents add the brightness emerald itself does not have.

Caring for Emerald: The Hard Rules

• Clean with lukewarm water, a drop of mild soap and a soft brush. Dry gently.
• Avoid solvents, acetone, bleach and heat.
• Put jewelry on last, after perfume and lotion.
• Store separately. Harder stones will scratch it.
• Have the setting checked periodically, and ask a jeweler about re-oiling if the stone looks duller than you remember.

Meaning and Tradition

Emerald is traditionally linked with rebirth, growth and renewal, which suits a spring birthstone. It is one of the four stones historically called precious, alongside diamond, ruby and sapphire, and it is commonly associated with the 20th and 55th wedding anniversaries. As with every birthstone, treat the symbolism as tradition and gift sentiment rather than fact about the stone.

Frequently Asked Questions