Emerald: meaning, properties and lore

The mineral

Emerald is the most famous member of the beryl family, and it is the bluish green to green variety of beryl, a mineral species that also includes aquamarine and beryls in other colours. Beryl is composed of beryllium, aluminum, silicon and oxygen, and the chemical formula of emerald is Be₃Al₂Si₆O₁₈.⁹¹²³⁸

Emerald has a Mohs hardness of 7.5 to 8, a specific gravity of 2.72, a refractive index of 1.577 to 1.583 and a birefringence of 0.005 to 0.009. Emeralds are more brittle than a gem like corundum, and they have fair to good toughness, so they need more care in wearing than ruby or sapphire. Because its density is lower, a one-carat emerald appears larger than a one-carat diamond.^14536810

Chromium, vanadium and iron are the trace elements that cause emerald's colour, and the presence or absence of each and their relative amounts set the exact shade of a crystal. If the hue is too yellowish or too bluish, the stone is not emerald but a different variety of beryl.¹⁰³⁷⁸

The best emerald crystals are flat-topped green hexagonal columns, and emeralds typically form in six-sided prisms, which is why they are naturally suited to the emerald cut. Emeralds are commonly cut as rectangular step cuts called emerald cuts because of the crystal shape. Natural emeralds form shallower in the Earth than diamonds, often within a few miles deep.¹⁷³

Almost all emeralds have significant fractures, sometimes called fissures in the trade, and most emeralds have inclusions that can be seen with the unaided eye. Inclusions are often described as looking mossy or garden-like, sometimes called jardin. Three-phase inclusions in Colombian emeralds contain tiny crystals of rock salt, liquid and a bubble of gas.¹⁰⁷¹

Colombia has been the source of the finest emeralds for more than 500 years, and Colombian emeralds are the standard by which all others are measured. Darker tones of pure green emeralds come from the Muzo locality, lighter-toned slightly bluish green stones are associated with Chivor, and slightly yellowish green emeralds are unearthed at Coscuez. Emerald is also found in the Brazilian state of Minas Gerais, including at the Belmont mine and the Capoeirana area. Zambia is a major source, with mines in the Ndola Rural Restricted Area producing bluish green, darker-toned emeralds, and Pakistan and Afghanistan are important producers. The oldest emeralds, from South Africa, are 2.97 billion years old.⁵¹

Emerald is a variety of beryl that is distinguished from green beryl by the depth of its green. The most valuable emeralds are bluish-green to green with a medium to medium-dark tone.³²⁷

Laboratory-grown emeralds have essentially the same physical and gemological properties as natural emeralds. Filling fissures with oil, wax or resin is the most common emerald clarity treatment. Some estimates state that 90 percent or more of emeralds are fracture-filled, and oils, resins and polymers are used to fill surface-reaching fractures. Emeralds with multiple fractures that are paler may be dyed green to enhance their colour.³⁴⁵

History and lore

Emerald's name comes from the ancient Greek word for green, smaragdus, and the Arabians called it Zamarut. Other language names include Smeraldo in Italian, Esmeralda in Spanish and Emeraude in French. Emerald has been the standard for green among colored stones for thousands of years.^9531110

The first known emerald mines were in Egypt, believed to have been worked as early as 3500BC, and the Gemological Institute of America gives the span from at least 330 BC into the 1700s. Cleopatra was a pharaoh known for her passion for emeralds and used the stone in her royal adornments. The Incas had used emeralds in their jewelry and religious ceremonies for 500 years before sixteenth-century Spanish explorers arrived in the New World.¹⁹⁷⁵

Pliny the Elder described emerald in his Natural History, published in the first century AD, saying nothing greens greener. Pliny described the greenness of the finest emerald as a gentle green that soothes weariness of the eyes, and recorded that early lapidaries used emerald to restore their eyes by looking at its soft green colour. Pliny and Solinus placed emerald in gold mines, where the Sephiran kind is said to be guarded by griffins.⁹⁵¹²¹¹

Spanish explorers traded emeralds from what is now Colombia for gold and silver. Sixteenth-century Conquistadors discovered South American emerald mines that had been hidden by the Incas, and Europeans fell in love with emerald after a ready and exceptional supply became available in that century. According to lore, the largest stone of the Crown of the Andes, now called the Atahualpa emerald, was taken from the last Inca emperor Atahualpa by Francisco Pizarro.⁹⁷⁵

Veltheim argues that the ancients' emeralds praised by Strabo were in fact green fluorspar rather than true emerald, and writes that the emeralds from the Egyptian-Arabian mountains, according to newer observations, are nothing more than green fluor-spar. Veltheim notes that the large emeralds of royal collections are generally flawed and not clear enough to serve as a lens for a myope.¹²

The First French Version describes emerald as surpassing all things in greenness through its colour. The First Prose Lapidary says emerald is of six kinds, one found in Scythia, one coming from Bractania, and one carried by the Nile from Paradise, and that it is found in Ethiopia, Cyprus and Africa. The Verse Adaptation says emerald is of five kinds, that the Arismapi people love it more than gold or silver and give it to griffins, and that Nero used a mirror of emerald to watch his amusements.¹³

Martinus Kulandus said an excellent emerald surpasses the watered grass, green herbs and all the glory of the Spring in its verdure. Emeralds were in times past forbidden to be engraved with anything, and the Oriental ones were valued at a quarter of a diamond of the same weight. Baccius said emerald is the house or palace of the Smaragde in the form of the Chrysoprasus, which is found either in it or affixed to it.¹¹

Legend states that emerald was one of four precious stones given by God to King Solomon, said to give the king power over all creation. Legend holds that emerald can make its wearer more intelligent and quick-witted. People throughout history believed emeralds conferred riches and power on their owners when worn as talismans.⁹⁵⁶³

Legends held that emerald placed under the tongue let the wearer foresee the future, reveal truth and be protected against evil spells. Wearing an emerald was believed to reveal the truth or falseness of a lover's oath and make one an eloquent speaker. Emerald was once believed to cure diseases like cholera and malaria.⁹⁵

Birthstone and zodiac links

Emerald is the birthstone for the month of May, a link given by the International Gem Society and the Gemological Institute of America. Emerald is also the gemstone given for the 20th and 35th wedding anniversaries. These are modern lists rather than ancient ones.^912714586

Modern writers often connect emeralds with spring and fresh starts, and the stone has long been treated as a symbol of rebirth and renewal.⁶³

What crystal practitioners say

Crystal practitioners associate emerald with the mind and with clear judgment. Believers hold that emeralds hold additional powers of persuasion beyond their physical beauty. Some cultural traditions held that emeralds could temper passionate feelings, allowing clearer judgment about partners.¹⁴⁶⁵

Throughout history, emeralds have been thought to possess powerful protective properties, acting as amulets that ward off evil, according to crystal practitioners. Lore of emerald is said to include seeing into the future, becoming an eloquent speaker, and defeating spells and enchantments. Emeralds are said to symbolize rebirth, prosperity, renewal and growth, making them suited to couples starting a new chapter.¹⁴⁷³

Practitioners hold that emerald relaxes the tissues around the eyes and restores the correct tone to the eye muscles, according to The Healing Crystals First Aid Book. To apply this, they place small crystals or tumbled emerald stones directly on the eyes or wear emerald as a necklace or pendant. Some also take emerald gem essence, five to nine drops three to five times a day, or drink gem water.¹⁵

Practitioners suggest that emerald, worn as a necklace or pendant after birth, can support milk production and ease grief or emotional crises. Practitioners hold that the stone helps people whose back problems are linked to feeling lost, injustice, disharmony, failure or fatigue.¹⁵

Bloating of any sort is said to be eased by emerald, whether taken as gem essence before meals or worn as a necklace. Acute bronchitis, particularly when it follows a rapidly worsening cold, is also believed to respond to the stone. Because traditional belief credits emerald with benefiting the eyes and treating assorted complaints, it is further associated with both sight and breathing.¹⁵¹⁴

What testing has found

Edzard Ernst, who analysed 150 complementary and alternative treatments, found no rigorous trials that test whether crystal healing has real therapeutic value. In his view, no scientific evidence shows any effect beyond placebo. He ascribes the pleasant feelings people report to a strong placebo response and to cognitive bias.¹⁶

In 2001, Christopher French tested 80 volunteers, asking them to distinguish genuine crystals from fakes after they had held the stones and meditated.¹⁶¹⁷

Some researchers suggest crystals probably do not act directly on physical or psychological problems, though any benefit might be indirect and explained by the placebo effect. Ted Kaptchuk, a Harvard Medical School professor, notes that some unconventional treatments can produce placebo results that patients find especially convincing. Scientific study of crystal therapy remains scarce, and the wider scientific community stays doubtful.¹⁷