precious stones: emeralds
By zteve t evans
Emeralds are beautiful and mysterious and are used as the centre piece in many items of marvellous jewellery or to enhance and flatter other gemstones and precious metals.
Part of a glittering obsession
Emeralds are part of a glittering obsession modern day society has with gems and precious metals that can be fashioned into items to flatter and decorate and can be an abstract expression of value, status and importance. Where do these wonderful gems come from and how are they valued?
Emerald producing regions
While many countries around the world produce emeralds, Columbia is regarded as the place where the most high quality emeralds are produced. Here there are around 150 known deposits, though not all of them are currently in production.
The mines of Muzo and Chivor, where the Incas mined their emeralds are the best known Columbian mines. Economically, the Coscuez Mine is probably the most important having around 60 working faces. This mine is estimated to produce around 75% of Columbia’s emeralds.
The colour of emeralds can vary slightly from source to source. Columbian emeralds tend to have less impairment and are a finer, shining green coloration, with less blue, than emeralds from elsewhere. This makes them highly desirable in the international emerald markets. Even stones that contain inclusions are highly regarded.
Rare Trapiche emeralds are sometimes found in Colombian mines. These have six rays like the spokes of a wheel that emanate from their centre and are much sought after.
Other sources of emeralds
Although Colombian diamonds are more prized there are other mines in other countries around the world that also produce high quality gemstones. For example, Zambia, Brazil, Madagascar, Zimbabwe, India, Pakistan, Russia and Afghanistan all produce high quality emeralds. Of these, Brazil, Zambia and Zimbabwe have a good reputation for producing fine quality emeralds.
Zambia
Emeralds from Zambia have a good transparency and are a beautiful deep green, darker and often with a gentle bluish overtone, than Colombian emeralds
Zimbabwe
The Sandawana Mine in Zimbabwe has a reputation for producing smaller, fine quality emeralds. These often are an intense and vibrant deep green with a slight yellowish tinge.
Brazil
The Nova Era Mine, in Brazil also produces high quality emeralds. These possess a glorious green coloration though by a small margin they are not considered to be as desirable as Colombian emeralds. Brazilian mines also produce emerald cat’s eyes which are rare.
Emeralds are part of a glittering obsession modern day society has with gems and precious metals that can be fashioned into items to flatter and decorate and can be an abstract expression of value, status and importance. Where do these wonderful gems come from and how are they valued?
Emerald producing regions
While many countries around the world produce emeralds, Columbia is regarded as the place where the most high quality emeralds are produced. Here there are around 150 known deposits, though not all of them are currently in production.
The mines of Muzo and Chivor, where the Incas mined their emeralds are the best known Columbian mines. Economically, the Coscuez Mine is probably the most important having around 60 working faces. This mine is estimated to produce around 75% of Columbia’s emeralds.
The colour of emeralds can vary slightly from source to source. Columbian emeralds tend to have less impairment and are a finer, shining green coloration, with less blue, than emeralds from elsewhere. This makes them highly desirable in the international emerald markets. Even stones that contain inclusions are highly regarded.
Rare Trapiche emeralds are sometimes found in Colombian mines. These have six rays like the spokes of a wheel that emanate from their centre and are much sought after.
Other sources of emeralds
Although Colombian diamonds are more prized there are other mines in other countries around the world that also produce high quality gemstones. For example, Zambia, Brazil, Madagascar, Zimbabwe, India, Pakistan, Russia and Afghanistan all produce high quality emeralds. Of these, Brazil, Zambia and Zimbabwe have a good reputation for producing fine quality emeralds.
Zambia
Emeralds from Zambia have a good transparency and are a beautiful deep green, darker and often with a gentle bluish overtone, than Colombian emeralds
Zimbabwe
The Sandawana Mine in Zimbabwe has a reputation for producing smaller, fine quality emeralds. These often are an intense and vibrant deep green with a slight yellowish tinge.
Brazil
The Nova Era Mine, in Brazil also produces high quality emeralds. These possess a glorious green coloration though by a small margin they are not considered to be as desirable as Colombian emeralds. Brazilian mines also produce emerald cat’s eyes which are rare.
Valuing emeralds – The Four Cs
Regardless of where they originate from, emeralds, like most other precious stones are valued in the same way. This is by color, clarity, cut and carat, and sometimes referred to as ‘The Four Cs’.
Color
Of these color is considered the most important and is rated by hue, tonal grade, and saturation. The most sought after emeralds are bluish green to pure green in coloration. They possess vibrant color saturation and a tone that is not excessively dark. They are very transparent and evenly colored with no shading visible to the naked eye.
Clarity
Inclusions are tiny flaws and fractures in the emerald and it is the quantity of these that defines the clarity of the emerald.
Cut
The cut is the final shape of the emerald and will be decided by how the stone’s natural qualities can best be enhanced. A good cut will display the emerald’s natural beauty to the best effect while reducing any visual effect there may be from inclusions.
Emeralds can be a difficult gemstone to cut. Their high market value makes it imperative that the stone is cut right. Although they are of a good hardness they often contain a number of small fissures known to be brittle. This complicates any cutting, setting and cleaning of the stone even for a skilled gem cutter.
A special square, or rectangular cut, with bevelled corners, has beet developed for emeralds that enhances the beauty and value of the gem to the full. This cut is also designed to protect it from the mechanical rigours involved.
Nevertheless, emeralds can be cut in many of the classical jewel shapes. If a gemstone does contain many inclusions it is often cut into small emerald beads that are popular in countries such as India, or it may be cut into a cabochon.
Carat
Carat is a standard unit of mass used for precious stones, equal to 200 milligrams. Emeralds come in many shapes and sizes. Some are large and weigh hundreds of carats while others are much smaller and only weigh a few. Large emeralds of good quality are rare and more expensive to find and consequently of greater value. A word of warning, though some large stones are not always of the best quality
Enhancements using oils and resins
After cutting most emeralds are enhanced using oils or resins to seal the minute fissures in the gems surface. Although this can make them more attractive the downside is that care is needed with their maintenance as they cannot be cleaned using an ultrasonic bath. If these enhancing substances are removed the stone can lose its sheen taking on a mat appearance. For this reason emerald rings should not be worn when washing dishes as the water will probably contain a detergent which can remove the seal from the outside of the stone.
Synthetic and imitation emeralds
The beauty and value of emeralds makes them a highly desirable gemstone to own. This has led to many substitute emeralds being used in jewellery. Because synthetic and imitations are readily available it can be difficult for a buyer to know if they are purchasing a genuine emerald and not a fake. It is always best for someone with little knowledge of gems to buy from a trusted and reliable source.
Buying emeralds
While small diamonds glitter, with emeralds and other coloured stones the bigger the more beautiful and lustrous they appear. The bigger they are the rarer and more expensive they are. A large emerald of top quality can be more expensive to buy than a diamond of equal weight. When buying it is important to think seriously about the financial resources available and the purpose for which the emerald is required to get the best possible value for money.
Highly valued gemstones
These precious stones are found and highly valued all around the world. Their natural beauty, wonderful coloring and rarity make them a highly valued gemstone.
© 06/10/2013 zteve t evans
Regardless of where they originate from, emeralds, like most other precious stones are valued in the same way. This is by color, clarity, cut and carat, and sometimes referred to as ‘The Four Cs’.
Color
Of these color is considered the most important and is rated by hue, tonal grade, and saturation. The most sought after emeralds are bluish green to pure green in coloration. They possess vibrant color saturation and a tone that is not excessively dark. They are very transparent and evenly colored with no shading visible to the naked eye.
Clarity
Inclusions are tiny flaws and fractures in the emerald and it is the quantity of these that defines the clarity of the emerald.
Cut
The cut is the final shape of the emerald and will be decided by how the stone’s natural qualities can best be enhanced. A good cut will display the emerald’s natural beauty to the best effect while reducing any visual effect there may be from inclusions.
Emeralds can be a difficult gemstone to cut. Their high market value makes it imperative that the stone is cut right. Although they are of a good hardness they often contain a number of small fissures known to be brittle. This complicates any cutting, setting and cleaning of the stone even for a skilled gem cutter.
A special square, or rectangular cut, with bevelled corners, has beet developed for emeralds that enhances the beauty and value of the gem to the full. This cut is also designed to protect it from the mechanical rigours involved.
Nevertheless, emeralds can be cut in many of the classical jewel shapes. If a gemstone does contain many inclusions it is often cut into small emerald beads that are popular in countries such as India, or it may be cut into a cabochon.
Carat
Carat is a standard unit of mass used for precious stones, equal to 200 milligrams. Emeralds come in many shapes and sizes. Some are large and weigh hundreds of carats while others are much smaller and only weigh a few. Large emeralds of good quality are rare and more expensive to find and consequently of greater value. A word of warning, though some large stones are not always of the best quality
Enhancements using oils and resins
After cutting most emeralds are enhanced using oils or resins to seal the minute fissures in the gems surface. Although this can make them more attractive the downside is that care is needed with their maintenance as they cannot be cleaned using an ultrasonic bath. If these enhancing substances are removed the stone can lose its sheen taking on a mat appearance. For this reason emerald rings should not be worn when washing dishes as the water will probably contain a detergent which can remove the seal from the outside of the stone.
Synthetic and imitation emeralds
The beauty and value of emeralds makes them a highly desirable gemstone to own. This has led to many substitute emeralds being used in jewellery. Because synthetic and imitations are readily available it can be difficult for a buyer to know if they are purchasing a genuine emerald and not a fake. It is always best for someone with little knowledge of gems to buy from a trusted and reliable source.
Buying emeralds
While small diamonds glitter, with emeralds and other coloured stones the bigger the more beautiful and lustrous they appear. The bigger they are the rarer and more expensive they are. A large emerald of top quality can be more expensive to buy than a diamond of equal weight. When buying it is important to think seriously about the financial resources available and the purpose for which the emerald is required to get the best possible value for money.
Highly valued gemstones
These precious stones are found and highly valued all around the world. Their natural beauty, wonderful coloring and rarity make them a highly valued gemstone.
© 06/10/2013 zteve t evans
References and attributions
Copyright October 6, 2013 zteve t evans
Copyright October 6, 2013 zteve t evans
- Wikimedia Commons - Cartier 3527518904 52f4a5dda6 CC BY-SA 2.0 - thisisbossi
- Wikimedai Commons - Natural History Museum - Chalk Emerald CC BY-SA 2.0 - Andrew Bossi from Laurel, MD, USA - 2009 04 19 - 4685 - Washington DC - Natural History Museum - Chalk Emerald
- International Colored Gemstone Association - Emerald
- GIA - Emerald Quality Factors
- GemSelect - Emerald Gemstone Information