May Birthstone is Emerald

Emerald is the birthstone of May and the gem of the twentieth and thirty-fifth wedding anniversaries.

Emerald is the gem that is always associated with the lushest landscapes and the richest greens; Ireland is known as the Emerald Isle. The first known emerald mines were in Egypt, dating from at least 330 BC into the 1700s. Cleopatra was known to have a passion for emerald, and used it in her royal adornments.

Emerald is the most famous member of the beryl family. Legends endowed the wearer with the ability to foresee the future when emerald was placed under the tongue, as well as to reveal truth and be protected against evil spells. Emerald was once also believed to cure diseases like cholera and malaria. Wearing an emerald was believed to reveal the truth or falseness of a lover’s oath as well as make one an eloquent speaker.


The most important quality factor for emerald is color. Emerald is the green to greenish blue variety of beryl, a mineral species that also includes aquamarine as well as beryls in other colors. The most important quality factor of emerald is color, with the most desirable colors being bluish green to pure green, with vivid color saturation and tone that’s not too dark. The most-prized emeralds are highly transparent with evenly-distributed color.


Emeralds typically contain inclusions that are visible to the naked eye. Because of this, many understand and accept the presence of inclusions in emeralds. Eye-clean emeralds are especially valuable because they’re so rare.


Cut is one of the most important factors in appearance. The most popular cut is the emerald shape due to the original shape of the crystals. Well cut stones maximize the beauty of the color while minimizing the impact of fissures, and creating a bright, lively stone.


Fashioned emeralds come in a wide range of sizes. There are emeralds in museums and private collections that weigh hundreds of carats. Quality-for-quality, the price of emerald can rise dramatically as the size increases.


Heat, light, and chemicals can damage the materials used to fill surface-reaching fractures.

Care and cleaning

Warm soapy water is always safe.


Most emeralds contain filled fractures; it’s risky to clean them ultrasonically or with steam.


  • MINERAL: Beryl
  • CHEMISTRY: Be3Al2Si6O18
  • COLOR: Vibrant green
  • REFRACTIVE INDEX: 577 to 1.583
  • BIREFRINGENCE: 005 to 0.009
  • MOHS HARDNESS: 5 to 8

(Gem Encyclopedia Emerald)