The May birthstone is emerald, the green to bluish green variety of the mineral beryl. Prized for its color since the time of the pharaohs, it is hard but often fractured, so it needs gentler care than most gems. By tradition emerald is a stone of spring, renewal and clear sight, and Colombia has supplied the finest examples for more than 500 years.
What is the birthstone for May?
Emerald is the only May birthstone on the American list used by Jewelers of America and the American Gem Society, and it has held the month since the list was standardized in 1912.
In Britain the National Association of Jewellers also names emerald and adds chrysoprase as an alternative. Chrysoprase is an apple-green chalcedony: opaque rather than transparent, and far less costly.
The tool below does the lookup for any date, May or otherwise, and adds the birth flower, zodiac sign and Chinese zodiac animal.
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What does emerald mean?
The name comes from the Greek smaragdos, "green gem," and green is the whole point. Writing in the first century, the Roman author Pliny the Elder declared that "nothing greens greener" and noted that gem cutters rested their tired eyes by looking at an emerald.
Emerald has been a royal stone on several continents. Egyptian pharaohs wore it, Cleopatra was famous for her emerald jewelry, and Inca emperors treasured it. The Crown of the Andes, made in colonial South America, is set with nearly 450 emeralds.
Over the centuries people credited the stone with a long list of powers:
- Wit and eloquence. An emerald was said to make its owner more intelligent and a better speaker.
- Foresight. Placed under the tongue, it supposedly let a person see the future.
- Truth in love. It was believed to expose a lover's false promises.
It was also once believed to cure diseases. None of this is true in any medical sense, and an emerald is not a remedy for anything. What remains is the association with spring, growth and fresh starts, which suits a May birthday well.
What color is the May birthstone?
Green, and only green. Emerald and aquamarine are the same mineral, beryl; the name emerald is kept for stones colored a rich green, traditionally by traces of chromium. A beryl that is too pale is called green beryl instead, and gemologists themselves disagree about exactly where emerald begins.
Color also hints at origin. According to the Gemological Institute of America, Colombia's three famous mining areas each have a look: Muzo stones tend to a darker pure green, Chivor to a lighter, slightly bluish green, and Coscuez to a slightly yellowish green.
Expect to see inclusions. Clean emeralds are rare, and small internal features are accepted far more readily than in a diamond.
Why most emeralds are treated
Most emeralds have fractures that reach the surface, and nearly all are treated to make those fractures less visible.
- Fracture filling. Oils, waxes and artificial resins are used to fill surface-reaching fractures and improve apparent clarity. The amount of filler ranges from minor to significant, and some fillers are more stable than others.
- Dyeing. Pale stones with many fractures are sometimes dyed green.
Treatment is normal for emerald and not a sign of a fake, but it affects both value and care. Ask the seller what has been done to the stone, and for an expensive purchase ask for a laboratory report.
Where emeralds come from
Colombia has been the source of the finest emeralds for more than 500 years and is the standard against which others are judged. Brazil's state of Minas Gerais is a major producer, with the large Belmont mine among its operations. In Africa, Zambia yields emeralds that are bluish green and darker in tone. Pakistan and Afghanistan are also important sources.
How to care for emerald jewelry
Emerald rates 7.5 to 8 on the Mohs scale, harder than quartz. The weakness is not hardness but the fractures and the filler inside them.
- Wash it gently in warm, soapy water with a soft brush. This is the safest method.
- Never use an ultrasonic cleaner. The vibration and heat can make the filler sweat out of the fractures. Skip steam as well.
- Keep it away from heat and hot water. Even very hot dishwater can damage a filled emerald, so take rings off at the sink.
- Avoid harsh chemicals and sudden changes in air pressure.
- Protect it from knocks. Choose a setting that shields the stone, and take emerald rings off for sport, gardening and housework.
Emerald gift ideas for a May birthday
- Earrings or a pendant are the safest way to wear emerald, because they take fewer knocks than a ring.
- A ring in a protective setting, such as a bezel or a halo of small diamonds, for someone who wants to wear the stone every day.
- Small but green. A small emerald with strong color looks better than a large pale one, and costs less.
- The alternative. Chrysoprase gives the color of May in beads, cabochons and signet rings at a modest price.
- At the top end, fine color, good transparency and little treatment are what raise the price.
Emerald also marks the 20th and 35th wedding anniversaries; see our guide to gifts for every wedding anniversary.
May birth flowers: lily of the valley and hawthorn
May's birth flowers are lily of the valley and hawthorn. In the traditional language of flowers lily of the valley stands for sweetness, humility and the return of happiness. Hawthorn, a small tree covered in white blossom in late spring, stands for hope. White bells of lily of the valley against green leaves echo the color of an emerald. The symbolism is folklore, of course, but it makes a card easy to write. Every month's pair is in our guide to birth flowers by month.
Shopping for another birthday? Diamond belongs to April and June has pearl, alexandrite and moonstone; the rest are in birthstones by month.