Emerald, known for its ravishing green hue, is a variety of the mineral beryl. It contains trace amounts of chromium and sometimes vanadium, which give this gemstone its vibrant color. Emeralds join rubies and sapphires to form ‘the big three’ of colored stones. This stunning gem derives its name from an ancient Persian word for green, translated to Latin as “smaragdus”, and eventually over time, changed to “emerald”. Regarded as the most sought-after stone in the beryl group, the emerald continues to enthrall the world with its lush green color. With a hardness rating of 7.5 to 8 on the Mohs scale, emeralds make exceptional gemstones for all types of jewelry.
Ancient civilizations of Africa, Asia and South America were fascinated by emeralds ever since they were first discovered. The oldest emeralds in the world can be found in Zimbabwe, while Colombia is currently considered to be the best-known source for the ‘deep green’ variety of this gemstone. Brazil and Zambia are also regarded as the leading sources for fine-quality emeralds.
Naturally flawless emeralds are very rare and extremely valuable. Very often, emeralds with minute flaws are preferred over the flawless ones as they are considered to be more authentic. It has become a common industry practice to treat emeralds with oil or synthetic lubricants for enhanced clarity. Earrings and pendants offer a great way to showcase the beauty of this mesmerizing gem. Additionally, the captivating charm of emerald engagement rings has made it a popular choice among couples across the world.
Emerald is the birthstone for those born in the month of May. A symbol of rebirth, it is said to promote foresight, good fortune and youth. Emeralds are also believed to encourage growth, peace and balance. Green, by nature, is the most calming of all the hues on the color wheel, and emerald with its soothing green color offers relief from eye strain and stress. This gem was often used to decorate sacred images as well.
According to Rabbinic legends (the mainstream form of Judaism), God had granted King Solomon four precious stones that gave him the power to rule over all creations. One of these stones was an emerald. It was also believed that this gem protected the wearer from evil spells, and also gave the ability to foresee the future.
Throughout history, emeralds have been prized for their rarity and beauty. The Incas used them in their jewelry as well as in their religious ceremonies for over 500 years. One of the earliest known emerald mines was located in Egypt. Cleopatra, who’s believed to have been fascinated by the stone, used it in her adornments. The Egyptians also often buried emeralds with mummies with the hope that the stone would provide them eternal youth in the afterlife. Another interesting legend states that Roman Emperor, Nero watched the gladiator fights through an emerald, as the gem possessed the ability to soothe the eyes. This precious stone was also associated with Venus, the Greek goddess of love and beauty.
The vivid green hue of the emerald is often compared to lush green landscapes. Due to its green countryside, Ireland is often referred to as the Emerald Isle. Similarly, Seattle, located in the US state of Washington is called the Emerald City due to the greenery that surrounds it. This stunning gem has also featured in some of the world’s most iconic pieces of jewelry, including the necklace of Queen Marie Jose (the last royalty of Italy) that showcases around 50 stunning emeralds, and diamonds as well.
Hardness & Strength
Although an emerald is an excellent gemstone for most types of jewelry, it is more fragile than other forms of beryl. Emerald requires careful handling due to its naturally included and flawed formation. There’s a high possibility that it may develop additional internal cracks if subjected to extreme temperature change or rough impact. Extra care should, therefore , be taken while handling the precious emerald.
Natural emeralds, belonging to the beryl mineral family, tend to be more heavily included than any other kind of gemstone. These inclusions are caused by bits of liquids, gas and other minerals. In addition to internal inclusions, majority of emeralds also have tiny surface breaking fissures or cracks. Clarity enhancing treatments are widely practiced to improve their appearance and value.
Cedar oil, which is a colorless and viscous product from cedar trees, is used for treating emeralds. This oil is available in a very pure form and is beneficial for filling the fractures in an emerald. However, penetration into the tiny cracks of the emerald is difficult, as cedar oil is extremely sticky. For this reason, heat and pressure are sometimes utilized for better results. This process involves cleaning the emeralds and locking them inside a heated hydraulic cylinder with pure cedar oil. While the heat causes the cedar oil to liquefy, the pressure facilitates penetration into the tiny cracks of the gem. Once the stones are cooled, the cedar oil returns to its thick, viscous state and remains intact unless ultrasonic cleaners, excessive heat or harsh solvents are used.
The effect of the traditional oiling treatment is stable, but not permanent. Therefore an oil treated emerald will require re-oiling to maintain its luster. Non-standard treatments go beyond this and utilize colored oils and epoxy-like resins.
Quality and Grading
The color is the most important feature that determines the quality of an emerald. Other factors include cut, clarity and carat weight.
Emeralds in bluish green to deep green, with not a very dark tone and vivid saturation are the most preferred. The relative amounts of chromium, vanadium and iron determine the color of the stone. Emeralds that are highly transparent, devoid of any eye-visible color zoning are extremely sought-after. An evenly distributed color further elevates the overall appeal and value of the gemstone.
Emeralds are known to have visible inclusions, which are often described as garden-like or mossy. These inclusions are also referred to as ‘jardin,’ the French word for garden. The transparency and clarity of emeralds are closely linked. Eye-visible inclusions are generally accepted, but if these inclusions impact the transparency and clarity, it drastically reduces the value of the emerald.
Emeralds are susceptible to damage during polishing, cutting, setting and even careless daily wear. The 'emerald cut', also known as a trap-cut or step-cut, was specifically designed for emeralds. It protects the gem from mechanical strain and chipping. This cut (also used for other gemstones) helps maximize the hue, tone and saturation of the emerald, thereby enhancing its overall beauty. Besides the emerald cut, this gemstone is available in several other shapes, including oval and round.
Emeralds come in a wide variety of sizes. While emeralds in museums weigh hundreds of carats, there are also some that weigh a fraction of a carat. The smallest carat weights range from 0.02 to 0.50. Emeralds that weigh 1 to 5 carats are popular as center stones.
Based on color, clarity, cut and carat weight aspects, emeralds can be graded into the following categories:
In terms of quality, these are the top 1% of the emeralds available. They exhibit a truly exceptional rich green hue and are slightly included yet high in brilliance.
These emeralds are the top 10% of the lot. They radiate a rich, medium green color and have moderate inclusions.
This category features the top 33% of emeralds that have a medium green hue and heavy inclusions.
These are the top 75% of emeralds available that are dark green and opaque in appearance.
Emeralds have fair to good toughness, which means they require more care when compared to a ruby or sapphire. Keep the following tips in mind to maintain the beauty of this gemstone and to help them stay dazzling for years.
Avoid contact with harsh washing soaps and cleaners.
Do not wear your emeralds when engaging in any activity that might scratch the stone.
Use a soft toothbrush with diluted mild soap for cleaning, and do brush the underside of the emerald to ensure the removal of dirt and grease. Rinse with lukewarm water and pat dry.
Do not use ultrasonic cleaners, steam cleaners or acetone for cleaning as they can cause irreparable damage.
Exposure to high heat must be completely avoided.
Clean them only a few times in a year.
After years of wear, you may choose to have your emerald re-oiled by a local jeweler.