May's Birthstone: The Stunning Emerald

How did the emerald get its name?

The word 'emerald' is derived from the Old French word 'esmeralde', which is in turn derived from the Ancient Greek 'smaragdos', meaning 'green gem'. The name 'Esmeralde' is still fairly common girls' name. The heroine Esmeralde from the popular Disney film 'The Hunchback of Notre Dame' has vibrant emerald-green eyes (in the original Victor Hugo novel, she got her name because she always wore an emerald necklace). 

The origins of emeralds

Emeralds were originally discovered and mined in Egypt and were a favourite of Egyptian royalty. They maintained the monopoly on emeralds until the sixteenth century, when Spanish conquistadores forced the Inca to reveal their rich emerald mines, which had been in operation for at least five centuries previous. The green stones were cherished by the Inca and Aztec peoples for generations. Since the conquistadores brought South American emeralds to Europe, they have been considered the best specimens, however, mines also exist in Brazil, Zambia, Pakistan, the United States, Afghanistan, Russia and Australia.

Since the 1970s, Brazil has been a consistent source of emeralds. This is especially true today, with steady production from the Itabira/Nova Era belt in Minas Gerais. Gemstones Brazil’s emerald collection comes from a small cooperative based in Nova Era, created to help independent miners. We are always happy to give you more information about the origins of our emeralds if requested.

Identifying emeralds

Emerald crystals are formed in metamorphic rocks. Metamorphic transformation generally limits the size of emerald crystal formation, making them even rarer in larger sizes.

Emeralds are the bluish green to green variety of beryl. Beryl is clear in its purest form, but often contains impurities which give it varying colouration. Emeralds are coloured by trace amounts of chromium and sometimes vanadium. Almost all natural emeralds contain inclusions, and it is normal for them to be treated with oil or resin to fill tiny fissures and cracks. The presence of these flaws and oil make it quite easy to identify natural emeralds.

One of the easiest methods to identify emeralds is to test for their hardness. They are a durable gem, with a hardness of 7.5 to 8 on the Mohs scale. However, emeralds are softer than spinel, topaz and sapphire, and are generally more fragile than other beryls due to their naturally included state.

Gemological properties

Buying emeralds

There are lots of factors that you should take into consideration before you choose which kind of emerald or emerald jewellery to buy. This section will cover colour, clarity, cut, carats, and treatments, which can all affect the beauty and desirability of a gemstone. The above graphic is a useful resource, because it clearly shows the difference between colour, tone and hue, which are all factors that might affect your choices when selecting a gemstone.

Colour

Emeralds owe their fine green colour to traces of chromium and/or vanadium impurities. Colour is generally the most important quality factor, and it encompasses hue, tone and saturation. Saturation is the brightness (or purity, intensity) of a hue. The purer the hue, the higher grade it will get on the saturation scale.

In emeralds, the most desirable colours are vivid bluish green to pure green, with lots of depth; ideally, they will be neither too dark nor too pale, and the colour will be distributed throughout the gemstone. Traditional 'emerald green' should be the perfect balance of blue and yellow – a pure green hue.

Emeralds from different origins often have distinctive colours, although each deposit can have a large range of hues.

Clarity

Clarity  - the number, size and position of inclusions - is very important when you are evaluating a gemstone. However, inclusions are tolerated more in emeralds than virtually any other gem, because emeralds free of inclusions are extremely rare. Emerald clarity, unlike diamond, is graded by eye. If an emerald has no inclusions that are visible to the naked eye, it is considered flawless.

Almost all the emeralds contain jardins - the French word for gardens. These are entirely natural and can be embedded into crystals of other minerals, growth lines, cleavages or tiny fractures.

Many people believe that inclusions give a unique look and individuality to the gem, and they act as evidence of the stone's genuineness. They are a kind of code that can add to the character of the stone, so they are generally accepted.

Cut

The 'emerald cut' is a special cut developed just for emeralds. Due to the gemstone's hardness, it is brittle: this, along with the presence of jardins, can make it a challenging gemstone to cut and set. The emerald cut was specially created to protect the gem from mechanical strain caused by inclusions or cracks. The emerald cut is a rectangular or square shape with truncated corners. It was developed to show emeralds off to their best advantage while minimising the risk of fracturing or chipping. This cutting style maximises the beauty and colour of the stone.

Emeralds are also available in cushion, oval, round and other traditional cuts. Recently the smooth, dome-shaped cabochon cut has become very popular. Highly transparent and clear materials are sometimes cut with brilliant-style.

If an emerald is well cut, it will mask colour variation, inclusions and other imperfections, and not create 'extinctions' (dark patches). A well-cut gemstone should be well-proportioned and symmetrical, with no distortions. It should have sharp facet edges and flat faces, and should be free of chips and scratches. When polished, the gemstone should also possess good lustre - a quality is known as “vitreous”.

Here is one of the emerald cut that is available at Gemstones Brazil: 

Carats

The price of emeralds increases with its size like any other gemstone. Due to the rarity of clear big stones, a two carat emerald may cost several times more than a single carat emerald. 

Treatments

Oiling the emerald - to enhance its colour, mask inclusions and increase stability - is a common treatment, and there is nothing untoward about this centuries-old process. 'Oiling' refers to the practice of immersing emeralds in a colourless oil or resin. It doesn’t damage the gemstones and its effects dramatically improve the appearance of them. Most of the time, the process is done at the mining location. See the picture below for an emerald before and after oiling. 

The extent to which an emerald has been treated will affect its value – an emerald with good natural colour and clarity will always be more valuable than one whose qualities have been artificially enhanced. Therefore, any treatments done in a gemstone must always be fully disclosed.

Emerald history and lore

For thousands of years, since at least 330 B.C., almost all emeralds came from mines in Egypt - Cleopatra herself was said to have a particular love of emeralds. In 1817, Cleopatra's 'lost' emerald mines were rediscovered, but the supply of emeralds had long since been exhausted.

The Egyptian monopoly on emeralds endured until the Spanish conquistadores arrived in South America in the sixteenth century and conquered what is now known as Colombia. The Spanish found rich Incan emerald mines, and a ready supply of emeralds began to make their way to Europe.

Emeralds were also treasured by the Moguls of India - they loved emeralds so much that the stones were inscribed with sacred texts and worn as talismans. This led to the flourishing Jaipur cutting industry, which continues to this day. The holy scriptures of Hinduism, the Vedas, promote green gemstones as having properties that promote healing and good luck. 

Emeralds were celebrated in many other cultures. In Ancient Rome, its green colour was believed to be calming. In Arthurian legend, the Holy Grail is said to be formed from an emerald. In China, the emerald represented good luck, and in Ancient Egypt the emerald stood for fertility and rebirth. The emerald has always been seen as a symbol of fidelity, and during the Middle Ages it was believed that it would keep a woman chaste.

Emeralds are the birthstone of the month of May, as they are thought to symbolise the rebirth and renewal of the spring season. They are also the wedding anniversary gemstones for the 20th, 35th and 55th year of marriage.

Emerald jewellery

As emeralds are so stunning and precious, there are many exceptionally famous emeralds and pieces of emerald jewellery. 

Perhaps the most famous single piece of emerald jewellery in the world, the seventeenth-century Crown of the Andes features 453 stones with a total of 1521 carats. These include the 45 carat Atahualpa emerald, named after one of the last Inca emperors - the crown purportedly contains emeralds stolen from him. The crown was fashioned from a solid block of pure gold, originally as a decoration for the Madonna statue in the cathedral of Popayán, Colombia. Currently, the crown is in the collection of the Metropolitan Museum of Art in New York City.

The 632-carat Patricia Emerald (pictured) is considered one of the finest emerald specimens in the world. The dihexagonal crystal was found in Colombia in 1920, and was named after the mine owner's daughter. It is currently located in the American Museum of Natural History in New York.

Another of the world's largest and most famous uncut emeralds is the Devonshire emerald. It was given to the Duke of Devonshire by Emperor Dom Pedro I of Brazil in 1831, and weighs an impressive 1385.95 carats.

Iran's crown jewels constitute the largest collection of emeralds, with pieces mounted in a belt, necklaces, the royal throne and the famous Pahlabi Crown. The collection includes between 1500 to 2000 carats of emeralds.

The British royal family also favours emerald jewellery: Queen Elizabeth II has an impressive collection of emerald pieces, including the beautiful 'Vladimir Tiara'. This tiara was sold to the Queen's grandmother, Queen Mary, in 1921 by Princess Nicolas of Greece. It was one of Queen Mary's favourite pieces, and on her death it entered the personal jewellery collection of Queen Elizabeth. Although it can be worn with pearl drops, and without any pendants at all, it looks stunning with its emerald pendants (fashioned as a pendant option from the Cambridge emeralds, purchased at auction in 1918). 

Gemstone care

Emerald requires careful handling: it is sensitive to pressure and vulnerable to household chemicals. Emeralds can be scratched by harder gems such as topaz and sapphires. It is more fragile than other forms of beryl due to their naturally included and flawed formation. 

To clean your emeralds or emerald jewellery, you can use warm soapy water and a tissue or soft cloth. Make sure you rinse the stones well to remove soapy residue. Avoid ultrasonic cleaners and steamers, which can remove the oils used to enhance emeralds - regardless, most emeralds will need re-oiling occasionally to restore their colour and lustre. 

Store emeralds away from other gemstones and gemstone jewellery, ideally by wrapping them in soft cloth and placing them in a fabric-lined box.

Related gems

Emeralds belong to the beryl family of gemstones. There are several gemstone-quality varieties of beryl, such as aquamarine and morganite. There are also many other green gemstones that may be confused with emeralds, including demantoid garnet, tsavorite, chrome tourmaline, verdelite, flourite, and peridot.