Distinguishing Features
The oldest emeralds are believed to formed 2.97 billion years ago in South Africa.
The first known emerald mines were in Egypt. Some historians estimate that the Egyptians were mining emeralds as early as 3500 BC.
Cleopatra was known to have a passion for emeralds and used them in her royal adornments.
Three-phase inclusions in Colombian emeralds contain tiny crystals of rock salt, liquid, and a bubble of gas.
The Most Desirable Picks
Colour:
Colour is the most important quality factor for emeralds, the market considers emeralds to have the finest green among coloured stones. The most-prized emeralds are highly transparent. Their colour is evenly distributed, with no eye-visible colour zoning. The most desirable emerald colours are bluish-green to pure green, with medium to medium-dark tone, and strong to vivid colour saturation.
Clarity:
Emeralds typically contain inclusions that are visible to the unaided eye. These inclusions create an internal scene called “Jardin” or garden. Buyers usually understand and accept the presence of inclusions in emeralds because eye-clean emeralds are especially rare.
Cut:
Inclusions cause the rough stones to be vulnerable to fissures. The most popular cut is emerald cut due to the original shape of the crystals, which maximises the beauty of the colour with minimal weight loss in the cutting process.
Emeralds are widely cut in other shapes, too. Heavily included emeralds are often cut as cabochons.
Carat Weight:
Emeralds can be fashioned into tiny pieces or hundreds of carats. The price of emerald can rise dramatically as the size increase.
Origins
Origins in trade:
While emeralds may exhibit special characteristics representative of their source of origin, origin does not always guarantee quality. Traders and consumers should also avoid speculating on a gem’s source based on its appearance. A certificate from a prestigious independent gemological laboratory is a strong reference to identify the source. Many stones are marketed as “Colombian Emerald” or “Zambian Emerald” when their origins are uncertain.
It would be helpful to understand the general indicating qualities of the gems when they are associated with certain sources. However, bear in mind that appearances can be deceiving. A mine can produce gems of various qualities.
“Colombian” Emerald –is usually used to describe the finest emerald colour, characterised by a colour that is slightly bluish-green with medium to medium-dark tone and strong to vivid saturation.
“Zambian” Emerald –stones with a slightly darker tone, more bluish colour, and greater clarity than “Colombian” emeralds.
“Sandawana” Emerald – Dealers use this appellation to describe emeralds that resemble stones from Zimbabwe, characterised by their bright, intense colour, even in small size, and highly included state. Genuine Sandawana emeralds as small as 1 mm can still be a deep vivid green.
“Brazilian” Emerald – Dealers may use this term to describe emeralds with lighter tones and saturations approaching those of green beryl.
“Russian or Siberian” Emerald – Dealers may use this term to describe stones that are less bluish, more included, and lighter in colour than “Colombian” stones.
Sources:
Emerald is mined primarily from hard rock sources. A few emerald sources supply the great majority of emeralds in the global market, their characteristics may overlap, but some have unique traits to fit into specific market niches.
1. Columbia
Columbia mines were known for the intense green and sometimes large size emeralds. Most of the rough are cut domestically before they appear in the international market. Government geological studies suggest that even after centuries of mining, only 20 per cent of the country’s emerald deposits have been exploited. There is a huge potential of the industry on mining, manufacturing, and branding of columbian emerald.
2. Brazil
Brazil yields emeralds of a wide range of qualities. Most faceted emerald is from the Itabira, Nova Era, and Capoeirana areas.
3. Zambia
Zambia’s Kagem mine produces estimated 20 percent of the world’s emerald supply, but Jaipur in India is the leading cutting center of Zambian emeralds.
4. Central Asia
Panjshir Valley in Afghanistan, the Swat Valley in Pakisatan, and the area of Davdar are major sources of emerald in Central Asia.
5. Other Sources
Russia, Zimbabwe, Madagascar and China are other commercial emerald sources worldwide.
Significant Pieces
Worn by actress Elizabeth Taylor when she married Richard Burton in 1964, an emerald and diamond brooch is the most renowned jewellery made from emerald. It was sold in The Collection of Elizabeth Taylor: The Legendary Jewels Evening Sale at Christie’s in New York in December 2011. It realised $6,130,500, and remains the most expensive single stone emerald jewel ever sold, that's $280,000 per carat.
Another stunning emerald-and-diamond combination came in the form of a cascading necklace Burton gifted his wife on their wedding day. The necklace boasts 16 Colombian emeralds, each set off by a surround of pear-shaped and brilliant-cut diamonds. Taylor added her emerald brooch to the necklace as a pendant.
Formation
When beryllium, aluminium, silicon, oxygen and one or more of the colour causing trace elements, such as chromium, vanadium and iron, come together in the correct geological environment, natural emerald formation may occur.
Emeralds form in two main ways, one is with superheated water with the mixture of necessary elements under the correct pressure. The second way forms with magma instead. Both ways of formation in hydrothermal veins or magmatic pegmatites have enormous requirements, this is what make emeralds so rare and unusual.