Emerald (Zamurd) for May: What to Know Before You Buy

May's stone is the emerald - Zamurd in Urdu and Panna across much of the subcontinent. It is the most delicate of the "big three" coloured stones and the one where buyers are most often misled, usually by a stone that looks too perfect. For the story of the monthly list, see our birthstone guide.

The first rule: expect inclusions

Emerald is a green beryl, and the conditions that colour it also crack and include the crystal as it grows. A natural emerald nearly always shows something inside - often visible without a loupe. The trade calls this internal scenery the jardin, French for "garden".

So turn the usual logic around. A cheap emerald that looks completely clean is far more likely to be glass, a doublet (two pieces glued together) or a lab-grown emerald than a lucky find. What you are really looking for is inclusions that sit deep and quiet rather than ones that break the surface or cloud the stone.

How emerald is valued

1. Colour, by a long way. The top colour is a pure, saturated green with a slight blue tint, vivid but not dark. Paler or yellow-green stones fall into a lower class even at the same weight.
2. Transparency. Given that inclusions are normal, the question is whether the stone still looks bright and see-through or has gone cloudy and flat.
3. Size. Clean emerald rough is genuinely scarce, so price rises much more steeply with carat weight than it does for aquamarine, its sister beryl.
4. Condition. Emerald is brittle. Check the girdle and corners for chips, particularly on stones that have been in and out of settings.

Each listing on the emerald category page shows the price of that individual stone.

Oiling and filling

Almost every emerald on the market has had its surface-reaching cracks filled with oil (traditionally cedarwood) or resin so they show less. Light, traditional oiling is accepted throughout the trade. Heavy resin filling is a different matter and has a real effect on value. Neither should be hidden. We disclose treatments when known, and for an important stone you should ask for it in writing; a certificate is available on request and independent testing can be arranged.

Pakistan's own emerald: Swat

Pakistan is genuinely emerald country. Mines above Mingora in the Swat valley have produced fine bluish-green emerald since the 1950s, and Swat material is respected internationally, particularly for good colour in smaller sizes. When buying here, ask about origin - a stone from Swat carries a local story an anonymous import does not.

Care: gentle, always

Emerald is 7.5 to 8 on the Mohs scale, but hardness is not toughness: those internal fractures make it far easier to chip than a sapphire. Choose a protective bezel setting, and keep an emerald ring for occasions rather than housework or manual work. Never use an ultrasonic or steam cleaner - it drives the oil out and every fracture suddenly shows. A soft, damp cloth is all it should ever get.

Giving emerald

An emerald says "special occasion" - an anniversary, a wedding or a milestone May birthday. A modest Swat stone with good colour often makes a more personal gift than a larger, paler import, and a pendant or earrings keep it safer than a daily ring.

Panna in Vedic tradition

In the Vedic navaratna, emerald (Panna) is associated with Mercury (Budh) and is traditionally chosen by chart rather than by month. Read how the two systems compare in gemstones by rashi.

Choosing emerald at GemStore

We list emerald carefully and only when we are comfortable with the stone. Each one is photographed as it is, weighed and priced individually. Browse the emerald collection, read our detailed piece on identifying natural emeralds, and order with Cash on Delivery - you can inspect the stone before paying, with 7-day returns.