Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium and sometimes vanadium. Beryl has a hardness of 7.5–8 on the Mohs scale. Most emeralds are highly included, so their toughness (resistance to breakage) is classified as generally poor. Emerald is a cyclosilicate.
The word “emerald” is derived (via Old French: esmeraude and Middle English: emeraude), from Vulgar Latin: esmaralda/esmaraldus, a variant of Latin smaragdus, which originated in Ancient Greek: σμάραγδος (smaragdos; “green gem”).
Properties determining value
Emeralds, like all colored gemstones, are graded using four basic parameters–the four Cs of connoisseurship: color, clarity, cut and carat weight. Normally, in the grading of colored gemstones, color is by far the most important criterion. However, in the grading of emeralds, clarity is considered a close second. A fine emerald must possess not only a pure verdant green hue as described below, but also a high degree of transparency to be considered a top gem.
In the 1960s, the American jewelry industry changed the definition of emerald to include the green vanadium-bearing beryl. As a result, vanadium emeralds purchased as emeralds in the United States are not recognized as such in the UK and Europe. In America, the distinction between traditional emeralds and the new vanadium kind is often reflected in the use of terms such as “Colombian emerald”.
In gemology, color is divided into three components: hue, saturation, and tone. Emeralds occur in hues ranging from yellow-green to blue-green, with the primary hue necessarily being green. Yellow and blue are the normal secondary hues found in emeralds. Only gems that are medium to dark in tone are considered emeralds; light-toned gems are known instead by the species name green beryl. The finest emeralds are approximately 75% tone on a scale where 0% tone is colorless and 100% is opaque black. In addition, a fine emerald will be saturated and have a hue that is bright (vivid). Gray is the normal saturation modifier or mask found in emeralds; a grayish-green hue is a dull-green hue.
Emeralds tend to have numerous inclusions and surface-breaking fissures. Unlike diamonds, where the loupe standard, i.e. 10× magnification, is used to grade clarity, emeralds are graded by eye. Thus, if an emerald has no visible inclusions to the eye (assuming normal visual acuity) it is considered flawless. Stones that lack surface breaking fissures are extremely rare and therefore almost all emeralds are treated (“oiled”, see below) to enhance the apparent clarity. The inclusions and fissures within an emerald are sometime described as jardin (French for garden), because of their mossy appearance. Imperfections are unique for each emerald and can be used to identify a particular stone. Eye-clean stones of a vivid primary green hue (as described above), with no more than 15% of any secondary hue or combination (either blue or yellow) of a medium-dark tone, command the highest prices. The relative non-uniformity motivates the cutting of emeralds in cabochon form, rather than faceted shapes. Faceted emeralds are most commonly given an oval cut, or the signature emerald cut, a rectangular cut with facets around the top edge.
Most emeralds are oiled as part of the post-lapidary process, in order to fill in surface-reaching cracks so that clarity and stability are improved. Cedar oil, having a similar refractive index, is often used in this widely adopted practice. Other liquids, including synthetic oils and polymers with refractive indexes close to that of emeralds, such as Opticon, are also used. These treatments are typically applied in a vacuum chamber under mild heat, to open the pores of the stone and allow the fracture-filling agent to be absorbed more effectively. The U.S. Federal Trade Commission requires the disclosure of this treatment when an oil treated emerald is sold. The use of oil is traditional and largely accepted by the gem trade, although oil treated emeralds are worth much less than un-treated emeralds of similar quality. Other treatments, for example the use of green-tinted oil, are not acceptable in the trade. Gems are graded on a four-step scale; none, minor, moderate and highly enhanced. These categories reflect levels of enhancement, not clarity. A gem graded none on the enhancement scale may still exhibit visible inclusions. Laboratories apply these criteria differently. Some gemologists consider the mere presence of oil or polymers to constitute enhancement. Others may ignore traces of oil if the presence of the material does not improve the look of the gemstone.
Emeralds in antiquity were mined in Egypt at locations on Mount Smaragdus since 1500 BCE, and India, and Austria since at least the 14th century CE. The Egyptian mines were exploited on an industrial scale by the Roman and Byzantine Empires, and later by Islamic conquerors. Mining ceased with the discovery of the Colombian deposits; only ruins remain.
Colombia is by far the world’s largest producer of emeralds, constituting 50–95% of the world production, with the number depending on the year, source and grade. Emerald production in Colombia has increased drastically in the last decade, increasing by 78% from 2000 to 2010. The three main emerald mining areas in Colombia are Muzo, Coscuez, and Chivor. Rare “trapiche” emeralds are found in Colombia, distinguished by ray-like spokes of dark impurities.
Zambia is the world’s second biggest producer, with its Kafubu River area deposits (Kagem Mines) about 45 km (28 mi) southwest of Kitwe responsible for 20% of the world’s production of gem-quality stones in 2004. In the first half of 2011, the Kagem Mines produced 3.74 tons of emeralds.
Emeralds are found all over the world in countries such as Afghanistan, Australia, Austria, Brazil, Bulgaria, Cambodia, Canada, China, Egypt, Ethiopia, France, Germany, India, Italy, Kazakhstan, Madagascar, Mozambique, Namibia, Nigeria, Norway, Pakistan, Russia, Somalia, South Africa, Spain, Switzerland, Tanzania, the United States, Zambia, and Zimbabwe. In the US, emeralds have been found in Connecticut, Montana, Nevada, North Carolina, and South Carolina. In Canada, in 1997 emeralds were discovered in the Yukon.
Since the onset of concerns regarding diamond origins, research has been conducted to determine if the mining location could be determined for an emerald already in circulation. Traditional research used qualitative guidelines such as an emerald’s color, style and quality of cutting, type of fracture filling, and the anthropological origins of the artifacts bearing the mineral to determine the emerald’s mine location. More recent studies using energy dispersive X-ray spectroscopy methods have uncovered trace chemical element differences between emeralds, including ones mined in close proximity to one another. American gemologist David Cronin and his colleagues have extensively examined the chemical signatures of emeralds resulting from fluid dynamics and subtle precipitation mechanisms, and their research demonstrated the chemical homogeneity of emeralds from the same mining location and the statistical differences that exist between emeralds from different mining locations, including those between the three locations: Muzo, Coscuez, and Chivor, in Colombia, South America.
Both hydrothermal and flux-growth synthetics have been produced, and a method has been developed for producing an emerald overgrowth on colorless beryl. The first commercially successful emerald synthesis process was that of Carroll Chatham, likely involving a lithium vanadate flux process, as Chatham’s emeralds do not have any water and contain traces of vanadate, molybdenum and vanadium. The other large producer of flux emeralds was Pierre Gilson Sr., whose products have been on the market since 1964. Gilson’s emeralds are usually grown on natural colorless beryl seeds, which are coated on both sides. Growth occurs at the rate of 1 mm per month, a typical seven-month growth run produces emerald crystals 7 mm thick.
Hydrothermal synthetic emeralds have been attributed to IG Farben, Nacken, Tairus, and others, but the first satisfactory commercial product was that of Johann Lechleitner of Innsbruck, Austria, which appeared on the market in the 1960s. These stones were initially sold under the names “Emerita” and “Symeralds”, and they were grown as a thin layer of emerald on top of natural colorless beryl stones. Later, from 1965 to 1970, the Linde Division of Union Carbide produced completely synthetic emeralds by hydrothermal synthesis. According to their patents (attributable to E.M. Flanigen), acidic conditions are essential to prevent the chromium (which is used as the colorant) from precipitating. Also, it is important that the silicon-containing nutrient be kept away from the other ingredients to prevent nucleation and confine growth to the seed crystals. Growth occurs by a diffusion-reaction process, assisted by convection. The largest producer of hydrothermal emeralds today is Tairus, which has succeeded in synthesizing emeralds with chemical composition similar to emeralds in alkaline deposits in Colombia, and whose products are thus known as “Colombian created emeralds” or “Tairus created emeralds”. Luminescence in ultraviolet light is considered a supplementary test when making a natural versus synthetic determination, as many, but not all, natural emeralds are inert to ultraviolet light. Many synthetics are also UV inert.
Synthetic emeralds are often referred to as “created”, as their chemical and gemological composition is the same as their natural counterparts. The U.S. Federal Trade Commission (FTC) has very strict regulations as to what can and what cannot be called a “synthetic” stone. The FTC says: “§ 23.23(c) It is unfair or deceptive to use the word “laboratory-grown”, “laboratory-created”, “[manufacturer name]-created”, or “synthetic” with the name of any natural stone to describe any industry product unless such industry product has essentially the same optical, physical, and chemical properties as the stone named.”
In culture and lore
Emerald is regarded as the traditional birthstone for May as well as the traditional gemstone for the astrological sign of Cancer.
One of the quainter anecdotes about emeralds was told by the 16th-century historian Brantôme, who referred to the many impressive emeralds the Spanish under Cortez had brought back to Europe from Latin America. On one of Cortez’s most notable emeralds he had the text engraved, Inter Natos Mulierum non sur-rexit mayor (“Among those born of woman there hath not arisen a greater,” Matthew 11:11) which referred to John the Baptist. Brantôme considered engraving such a beautiful and simple product of nature sacrilegious and considered this act the cause for Cortez’s loss of an extremely precious pearl (to which he dedicated a work, A beautiful and incomparable pearl), and even for the death of King Charles IX of France, who died soon afterward.
The chief deity of one of India’s most famous temples, the Meenakshi Amman Temple in Madurai, is the goddess Meenakshi, whose idol is traditionally thought to be made of emerald.
The emerald has been a gem of fascination in many cultures for over six thousand years. It is so prized, that carat for carat, a fine emerald may be two to three times as valuable as a diamond. According to Indian mythology, the name emerald was first translated from Sanskrit as “marakata,” meaning “the green of growing things.” The name we know it as now is believed to come from an ancient Persian word, translated to Latin as “smaragdus,” and eventually over time, corrupted to “emerald.” Records show that the stone was known and sold in markets in Babylon as early as 4000 BC. It is a stone that was worshiped by the Incas and mentioned in biblical information about the apocalypse. The earliest reference to emeralds in Western literature come from Aristotle. He was a great fan of the gemstone and wrote that owning an emerald increases the owner’s importance in presence and speech during business, gives victory in trials, helps settle litigation, and comforts and soothes eyesight. He also stated “An emerald hung from the neck or worn in a ring will prevent the falling sickness (epilepsy). We, therefore, commend noblemen that it be hanged about the necks of their children that they fall not into this complaint.”
Many cultures throughout time have believed the emerald to be an enormously powerful stone in different ways. The Chaldeans believed the stone contained a goddess. And in the Islamic faith, an amulet of an emerald might be engraved with a verse from the Koran. The ancient Egyptians believed the emerald stood for fertility and rebirth. In Ancient Rome, Nero supposedly watched gladiator fights through a large transparent emerald as he found the color to be calming. In some legends of King Arthur, the Holy Grail is described as being fashioned from an emerald. In China, Thursday was the day for wearing green and emeralds for good luck. However, various countries in the East and West varied in opinion on which day the emerald would bring good luck. The Romans once considered light-colored Emeralds to be unripe, and believed that an Emerald becomes a darker shade of green as it matures.
There have been many beliefs that the emerald brings goodness into one’s life. The Roman magician Damigeron stated in the second century BC that an emerald “influences every kind of business, and if you remain chaste while you wear it, it adds substance to both the body and the speech.” The second century Mahabharata also commended the stone. The emerald has always been seen as a symbol of fidelity. During the Middle Ages it was believed that it would keep a woman chaste. Not surprisingly, the same was not believed to be true for a man. In various languages, it was also stated that emeralds enable people to foretell future events if put on the tongue or worn on the left side of the body. Emeralds were also believed to reveal what was true or false and was said to be a sure antidote for enchantments and spells. They were also to give eloquence in speech and make people more intelligent and honest. It is believed that emeralds contain the energy that is necessary to bring creative form to your work. And it was once believed that a high quality emerald would change hues to alert the wearer to impending danger. They also help one express love, devotion, and adoration.
It was known that Emerald was a favorite gem of Cleopatra, the Queen of Egypt, and the Emerald mine in Upper Egypt, rediscovered a hundred years ago near the Red Sea, which was one of the earliest Emerald occurrences in the human history. Emeralds also adorned Russian crown jewels. The Irani State Treasure contains an exquisite collection of Emeralds, as well as the Emerald tiara of ex-Empress Farah. Shah Jahan, one of the moguls of India that built the Taj Mahal, loved Emeralds so much that he had sacred texts inscribed into them and used these gemstones as talismans. The ancient writings of Veda, the sacred text of Hinduism, testifies to Emerald as being the “gem of good luck” and the “gem that improves one’s well-being”. These “Mogul Emeralds”, as they are known today, can be found in modern museums and collections.
Legend has it that Hernando Cortes, the conqueror of Mexico, tried to bring huge chunks of Emerald that he took from the Aztecs back home with him. However, one of his ships was shipwrecked, and delicately carved Emeralds in the shape of flowers and fish and other rare Emeralds, including an Emerald the size of a man’s palm, became lost forever.
Throughout history, emeralds have been prized and worn by royalty and celebrities. In the first century BC, Ptolemy, the King of Egypt, had an emerald engraved with the portrait of Lucullus, the great Roman general. He then presented it to him when Lucullus visited Egypt. Cleopatra’s mines (which now yield only poor quality emeralds) turned out many stones, a number of which are displayed in museums around the world, among other stones found 2000 years ago. Alexander the Great had a large emerald set into his girdle. Charlemagne had a collection of emeralds, and Henry II, when he was made King of Ireland in 1171, was given a large emerald ring. Queen Elizabeth II had an amazing collection of emerald jewelry including an emerald diadem. In modern times, Marlene Dietrich wore her own collection of dramatic jewelry set with huge cabochon emeralds (two bracelets and a clip brooch) in many of her movies. Grace Kelly, another icon, was given a 12 carat emerald cut diamond engagement ring from Prince Rainier. We have also seen the elegant Elizabeth Taylor in her emerald jewelry in National Geographic’s emerald story. Richard Burton gave her the emerald and diamond brooch as an engagement present, which she wore with an emerald necklace he gave her as a wedding present. Earrings, a bracelet, and a ring followed. Some of the emeralds in Taylor’s set were from the Grand Duchess Vladimir in Russia. John F. Kennedy gave Jacqueline Bouvier a 2.88 carat diamond emerald ring. And Sharon Stone was given a three diamond, 3 1/2 carat emerald-cut diamond engagement ring by Phil Bronstien.
Mystical Powers of Emerald
The ancients associated Emerald with the Greek goddess Venus, the goddess of love and beauty, it and was said to protect lovers from unfaithfulness. If the heart was loyal, the gem would glow in a beautiful green color, but if the heart was went astray, it would turn a different, lifeless color. In addition, it was believed that wearing an Emerald would improve one’s memory and intelligence, enabling one to think clearly about the past, present, and future.
Emerald plays a vital role in religion, as well. Green is the holy color of Islam, and the states belonging to the Arab world possess green banners symbolizing the unity of Islam. In the Catholic Church, green has a special meaning as well, since it has always been considered the most natural and elementary color in liturgy. Some say that an Emerald in a shape of a bowl fell off the Satan’s crown. That bowl was later used by Christ at the last supper, and Joseph of Arimathea caught Christ’s blood dripping from the cross in that bowl, founding the order of the Holy Grail.
Since as far back as there is evidence of emeralds, there has been evidence of its healing powers. Some said emeralds would heal if simply worn, others said gaining help required gazing deeply into the green for a while. In every language, there were reports of the emerald helping eyesight. The Sumerians said that if an emerald was worn in a ring on the little finger of the left hand, it would cure inflammation of the eyes. During the time of Hippocrates, emeralds were crushed into a fine powder and made into an eye lotion.
The emerald’s healing powers have been associated with the skeletal system, the flesh and skin, the cardiovascular system, the adrenal glands, the kidneys, liver and intestinal system. The stone is also considered to be very cleansing and prevents infection and diseases. It was once believed that a mother who wears emeralds keeps her child safe from complications during childbirth. Paracelsus recommended the emerald be ground up with laudanum, an opium derivative, as a medicine for certain fevers and ailments. There are many ailments that are believed to be cured by emeralds. Disorders that emeralds have been used for include colic, burns, ulcers, headaches, tension, influenza, epilepsy, high blood pressure, heart disorders, neuralgia, cancer, skin disorders, dysentery, syphilis, fevers, nausea, vomiting, indigestion, asthma and anemia. The emerald was also once prized as an antidote in cases of poisoning. Even today, the powder of poorer quality emeralds is used in folk medicines in China.
For the mind and the spirit, the remedial use of emeralds has many positive attributes. It is said to detoxify negativity and transform it into positive emotional energy. It stabilizes, soothes, and offers a sense of security, harmony and a closeness to God. It increases one’s life purpose in relation to the universal plan, and aids in emotional life and life transitions. It keeps the mind in excellent condition and also promotes a healthy memory. In today’s world, it is therefore an excellent stone for someone who is involved in public speaking. Emeralds are known to be calming and balancing, promoting creativity and eloquence and restoring faith and hope. They are believed to bring good fortune and are used to kindle kindness and sympathy. They are also used to improve one’s intuition, thereby increasing one’s perception. They bring truthfulness and are symbols of love. There have even been times in history when the emerald was believed to be able to control one’s passions and lusts. Today they represent the balance between Perfect Love and Perfect Trust while carrying the virtue of protection.
Physical Properties and Science of Emerald
Emeralds are found in granites, pegmatites, and schists, as well as alluvial deposits. Some emeralds find their way into gravels where the action of the water tumbles and smoothes them so they resemble shiny pebbles. The first known emerald mines were in Southern Egypt and show evidence of being worked in since 2000 BC. Some of the finest stones today come from Columbia, the best ones from the Chivor and Muzo mines. Much smaller quantities of medium-light color emeralds come from Brazil. Emeralds also come from Austria, India, Australia, Brazil, South Africa, Egypt, the USA, Norway, and Pakistan. In the last few decades, increasing quantities of emeralds have also been found in Zimbabwe, Zambia and Tanzania. These stones tend to be a very strong color, as are the stones from India, Pakistan and the Soviet Union.
Only the finest quality emeralds are clear and flawless. Most have tiny mineral inclusions or fractures, referred to as “jardin,” from the French word meaning garden. This refers to the moss or branch like appearance of the flaws. Flawless emeralds are rare and extremely valuable and usually only found in small sizes. There are fewer fine large emeralds in the world than there are diamonds! Most large emeralds have cracks and flaws, or are cloudy in color. It is common to oil these emeralds to disguise the flaws and enhance the color. The inclusions are sometimes not visible to the naked eye, especially in high quality stones. In these, they are very faint and only show up in a 10x, 20x, or 40x lens.
Emeralds are brittle and easily fractured during handling and setting. They are classified with a hardness of 9. They are not as hard as diamonds, but do last a long time. They scratch easily but the scratches can be wiped off. Emeralds range in color from light to dark green. The shade of green is determined by the presence of chromium oxide and vanadium. Throughout history, the emerald’s green color is said to have “entranced humankind.” Its color is a symbol of new life and the promise of spring, which is why it is the birthstone of May. Some call the green color of an emerald rich grass green, or limpid, velvety grass green, or deep transparent grass green with a luster. A square cut to the emerald actually emphasizes the richness of color by leading the eye into it rather than deflecting attention away from it. Some people actually prefer the off shades of green that are not perfect.
In ancient times, many gemstones were called emeralds just because they were green. Today there are about six or seven types of stones that are called various different kinds of emeralds. A true emerald however, is called simply an emerald, with no qualifying name in front of it.
Caring for your emerald jewelry
Do not leave your emerald ring on while washing dishes or using soap as an emerald will attract grease and soap. After a while, these substances will accumulate on the bottom of the gemstone, causing it to lose its lively brilliance. Also do not wear your emerald when you might be engaging in physical activity that might scratch the stone. To clean your emerald, use room temperature running water and a soft toothbrush with mild soap like hand soap or Woolite. Brush repeatedly on the underside of the emerald to remove accumulations of dirt and grease. You will see the emerald begin to brighten. It should then be rinsed with warm water, and patted dry.
Do not clean an emerald in ultrasonic cleaners, steam cleaners or acetone. These may cause damage to the stone or the setting. An emerald should never be exposed to high heat. A good rule of thumb is that if the cleaning solution you use is too hot for you to put your hand in, you should not place your emerald in it. Avoid using strong soaps, jewelry cleaner liquids or other cleaners as most of these are not compatible with the oil treatment of Emeralds. Cleaning should be done no more frequently than is necessary, and never more than several times a year. After many years of wear, you may wish to have your Emerald re-oiled. Most local Jewelers can provide this service.