THE EMERALD FACT SHEET
This section is dedicated to emeralds and
covers everything you need to know about this gem: from its origins and history to treatments and colour as well as other useful facts.
Who is this page for?
This page is useful for anyone working with gemstones. If you are a jeweller, then there is practical information such as hardness, weights by size and other useful facts. If you are a jewellery designer, you might find the sections on colour, origin and availability more interesting. You might work as a salesperson in a shop and are involved with the selling of jewellery with gemstones in. You might find origin, treatments and certificates more useful. If you just love looking at emeralds and want to further your general knowledge on the subject, you’ll enjoy the whole thing.
This is not a gemology course. It is an overview, to give you some practical information you might need while working with, or looking at emeralds. If you want more information, you can either contact us directly, or look at some of the links below relating to emerald knowledge.
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As gemstone suppliers based in London, Geneva and Tel Aviv, we feel it is essential to give you all the knowledge you need to work with emeralds more confidently. All the gemstones you see on this website belong to Haruni Fine Gems and are backed by a money back guarantee and free shipping worldwide.
If you would like any more information on the gems on this website, just contact us via the form on the gem page itself, chat, email, or call us at the number at the top of the page.
Pages connecting to the HUB
Below are essential snippets of information relating to emeralds. Click the header of each section to read more into each topic.
The Beauty of Emeralds
All You Need to Know about Emeralds
May Birthstone - the Magnificent Emerald
OVERVIEW
INTRODUCTION
Mined in Egypt as early as 3500 BC and by ancient Romans in the European Alps, emeralds are ancient gemstones admired by people for thousands of years. Incas and Aztecs offered them to their gods and preferred death over giving up their sources of the green crystal to the Spanish conquistators. From this time forward, royalty in many different countries looked to South America for a supply of the beautiful green emerald stones to adorn their jewellery and crowns. Emeralds have been thought to strengthen memory and wisdom.
Emerald is the birthstone for May and the Zodiac gemstone for Pisces. They are also recommended for couples celebrating their 55th wedding anniversary
ORIGIN
The origin of a gemstone can greatly affect its value. It is more important in rubies, sapphires and emeralds than in fancy colour diamonds, with the exception of pink Argyle diamonds.
Emeralds have traditionally been mined in South America, namely Colombia and Brazil. In more recent times, South Africa and Zambia in particular has been great source of emerald as well as a newly discovered source in Ethiopia.
Colombia – more desirable.
Zambia – made more popular by Gemfields.
Afghanistan and Brazil – Supplies very small stones to the market.
HARDNESS
Emeralds have a hardness of 7.5 on the Mohs scale of mineral hardness. Most emeralds are highly included, so their resistance to breakage is classified as generally poor. Yes, emeralds are not as hard as the other gemstones, but they can still be used in creating and adding style to jewellery without any worry, just some care.
TREATMENT
Due to fissures, inclusions, and tonal variations, emeralds are almost universally treated prior to marketing. Generally, an oil treatment is used, with cedar oil being the most traditional, although a number of synthetics compete with it at present as they tend to be permanent, while natural oils will dry out. Treatment can have a dramatic effect on the look of a stone, but discerning consumers will insist on a treatment report. Heavily treated stones will be worth less than one that is not, all other things being equal.
Most emeralds are treated with colourless oil or polymer resin. This improves the appearance of fractures. As natural oils tend to dry out over time, some maintenance is needed to re-oil a stone. Synthetic resins will not dry out. All treatments must be disclosed.
Dyeing is also a common treatment in some areas, but it is much less acceptable and must be disclosed. A simple test for this is to rub a little alcohol on the stone, if the green comes off in your fingers, it is colour enhanced.
LOOKING AFTER EMERALD JEWELLERY
Emerald is generally a brittle stone that usually contains fissures and could be easily chipped. This brittleness may have an influence on design and setting of emerald jewellery. You might want to be a little more careful with it and avoid things like gardening whilst wearing the ring. However, there are plenty of emerald rings that survive generations so wear happily, but with care.
COLOUR
While emeralds may have a number of colourations for an undertone their primary pure green generates the highest value. Additionally, emeralds are not graded at loupe magnification but rather by eye, so an emerald without flaws visible to the naked eye is considered flawless even if fissures appear under magnification. An emerald that is flawless under magnification is exceptionally rare and very valuable.
EMERALD WEIGHT AND MEASURES
One of the most useful tools a jeweller can have at their disposal is an understanding of how much gemstones of a certain size weigh. In the chart below, we give an overview of what different shaped sapphires weigh in different sizes
| Oval-"mm" | 4x3 | 5x3 | 5x4 | 6x4 | 7x5 | 8x6 |
|---|---|---|---|---|---|---|
| Emerald | 0.17 | 0.25 | 0.35 | 0.47 | 0.75 | 1.1 |
| Round-"mm" | 2 | 2.5 | 3 | 3.5 | 4 | 5 |
|---|---|---|---|---|---|---|
| Emerald | 0.03 | 0.06 | 0.1 | 0.17 | 0.26 | 0.52 |
| Octagon-"mm" | 5x3 | 6x4 | 7x5 | 8x6 | 9x7 | 10x8 |
|---|---|---|---|---|---|---|
| Emerald | 0.32 | 0.6 | 1 | 1.75 | 2.5 | 3.3 |
| Pear-"mm" | 5x3 | 6x4 | 7x5 | 8x5 | 9x6 | 10x7 |
|---|---|---|---|---|---|---|
| Emerald | 0.23 | 0.41 | 0.65 | 0.95 | 1.4 | 2.4 |
| Marquise-"mm" | 4x2 | 5x2.5 | 6x3 | 7x3.5 | 8x4 | 10x5 |
|---|---|---|---|---|---|---|
| Emerald | 0.08 | 0.16 | 0.25 | 0.37 | 0.6 | 1.1 |
GRADING EMERALDS
While Cut, Clarity, Colour and Carat weight are important when grading gemstones, value is most heavily weighted against its colour, as opposed to white diamonds, where the cut proportions and clarity are other primary indications of value. As a general rule, the more intense the colour, the rarer and more valuable the stone.
With rubies, sapphires and emeralds, the principles are the same, but not so easily quantifiable.
COLOUR
Colour is always going to be top of the list when grading gemstones, as with diamonds. With colored stones, the uniformity, beauty and quality of the colour is a primary determinant of quality and value.
Emerald’s main colour is green, also with secondary hues of yellow or blue. The purer the green the finer the stone.
CUT
With colored gemstones, the intricacy of the cut does not affect the beauty and the reflection of light of the stone in the same way that it will for a ‘white’ diamond or colored diamond. Colored stones have their own natural “glow”, which is only enhanced by the quality and style of the stone’s cut.
A simple cut can showcase the high points of a colored stone just as well as a complex cut. Unlike diamonds, a higher number of facets will not influence the values of the stone. In fact sometimes it may detract from the potential beauty of the stone.
CLARITY
Clarity refers to the stone’s lack of inclusions. It is worth noting that inclusions in colored stones are exceptionally common and only influence the price of a stone to a degree.
Unless the stone is eye clean, or loupe clean, which can fetch a much higher price, conversely opaque stones will be a lot cheaper.
CARAT
Emeralds and other gemstones are weighed in metric carats: one carat is equal to 0.2 grams, about the same weight as a paperclip.
Just as a dollar is divided into 100 pennies, a carat is divided into 100 points. Because even a fraction of a carat can make a considerable difference in cost, precision is crucial.
TREATMENT
Generally speaking, most gemstones undergo some treatment process. I would go so far as to say that it is normal for rubies, sapphires and emeralds to have undergone some treatment or another and is quite acceptable, providing it is disclosed.
Whether you have an emerald, or treated one, or it’s synthetic for that matter, all information pertinent to any enhancement process done to a natural gemstone must be disclosed when:
- the stone has undergone any treatment process; or
- the treatment is not permanent and its effects are lost over time (e.g. oil in emeralds); or
- the treatment creates special care requirements for the gemstone to retain the benefit of the treatment (e.g. oil in emeralds); or
- the treatment has a significant effect on the value of the gemstone (e.g. heat treatment in rubies and sapphires, or oil, or resin in emeralds, or irradiation in diamonds).
Why is this so important? Principally to tell you if stones have undergone any treatments that may affect their value. As the gemstone and diamond business has become more accessible, it has also become the target of fraudsters and criminals, looking to cheat buyers out of their hard earned money. There are websites and Facebook groups dedicated to these scams and the stories are endless. Fraud affects both the end consumer and those inside the trade. So it is reasonable for consumers to demand full gemstone descriptions including certificates and lab verification of value points on stones, especially for larger or more expensive pieces. Thus, familiarity with the major laboratories and certificates issued has never been more relevant.
ORIGIN
Colombia is the most famous source of quality emeralds. The most popular deposit in Colombia can be found in the mines of Bogota. It produces the finest quality emeralds of deep green color. However, only one-third of the emeralds found in the North East of Bogota are worth cutting.
Brazil is also another important supplier of quality emeralds. As compared to Colombian emeralds, Brazilian emeralds are lighter in colour and normally free of inclusions. Another popular source of fine emeralds is Africa. The East African emeralds are very rich in color and quite often found with the desirable blue-green hue.
Emeralds of important value are also found in the mines of Zimbabwe. They tend to be tiny in size yet extremely vivid in colour. Despite the tiny size, these intensely green emeralds are of very high quality.
Zambia is also known for mining deep green rough emeralds like Colombian mines. Zambian emeralds normally have a darker tone and produce more bluish green hues compared to Colombian emeralds. Emeralds are also found in Afghanistan, Madagascar, United States, India, Russia and Pakistan.
EMERALD CERTIFICATES
When working with coloured gemstones and diamonds, today more than ever, it is important to be able to have the stones independently evaluated. It is for this reason the gemstone laboratories have become vital players in the gemstone industry.
Why? Principally to tell you if stones have undergone any treatments that may affect their value. As the gemstone and diamond business has become more important and more accessible. It has also become the target of fraudsters and criminals, looking to cheat buyers out of their hard earned money. There are websites and Facebook groups dedicated to these scams and the stories are endless. And they affect both the end consumer and those inside the trade.
So it is reasonable for consumers to demand full gemstone descriptions including certificates and lab verification of value points on stones, especially for larger or more expensive pieces. Thus, familiarity with the major laboratories and certificates issued has never been more relevant.
LET’S LOOK AT EMERALDS
WHAT’S NEXT
- Bookmark this page
- Learn more about Emeralds
- Look at some Emeralds
- Download a copy of this guide for future reference:
Bonhams Fine Jewellery Sale Results
Fura Gems Unearths 25.97 ct Emerald
Queen Victoria’s Jewels on Display at Kensington Palace
