Buying an Emerald can be a very fun experience but it can also be a challenge and that is why I want to give you some tips so that you can make an informed decision to help you buy your perfect Emerald. All the tips below have come from many years studying, buying and selling these gorgeous green gemstones.
What is an Emerald?
It is always useful to understand a bit of information about a gemstone before you go and buy one, so here is a little bit of information about Emeralds.
- Emeralds are part of the Beryl family, which also includes Aquamarine, Heliodor and Morganite
- The beautiful green colour of Emeralds is caused by the element Chromium. While Chromium produces one of the finest greens in the world, it is also the reason why Emeralds are more brittle than the other members of the Beryl family. Nearly all natural Emeralds have at least on internal fracture.
- Emeralds measure 7 1/2 on the Mohs hardness scale. This means they are more likely to be chipped or scratched than a Ruby, Sapphire or Diamond
- The combination of being quite brittle and not that hard means that Emeralds are not the best choice of gemstone for a ring, they are far more suitable for earrings or pendants
- Birthstone Month: May
- Anniversary: 20th, 35th and 55th
Quality factors that affect the price of an Emerald
Clarity
As I said above, the majority of Emeralds on sale will have some fractures due to how brittle they are. The most desirable clarity for an Emerald is ‘eye clean’, this is when the amount of fractures and/or inclusions are difficult to see or cannot be seen by the naked eye and these stone generally attract higher premiums.
When buying an Emerald, you want to buy a stone that is as free from fractures as possible as this will help to extend the life of your stone. Highly fractured stones will be more likely to result in a broken stone.
Colour
Emeralds are traditionally known for their deep, rich green colour but this is also the most expensive colour.
Colour quality in Emeralds can vary quite a lot and the more undesirable colours are a very pale green, a light lime green colour and a very dark, almost black green. Ideally you want a stone that falls somewhere between the vary pale and very dark colours.
Cut
Due to Emeralds being a soft and brittle stone, the style of cut does have a big impact on the overall durability of the stone. Ideally you want to avoid any styles of cut with a point such as square, baguette, marquise or pear.
This is because the point of the stone will be weak and susceptible to damage. It is also the reason why Emeralds are the only stone to have a cut named after them. The Emerald Cut was devised as when they cut Emeralds into a baguette style cut, they would find that the corners would be easily chipped off. So they truncated the corners of the cut to prevent them from getting broken off.
Carat
As with many gemstones, the larger the size and weight, the more they cost per carat and it is no different with Emeralds, especially high quality ones. Due to their brittle nature, many Emerald crystals do not grow that big and that is why Emeralds weighing over 3 carats cost considerably more than smaller stones.
Treatments
It is estimated that over 90% of the Emeralds for sale at any given time have been treated or enhanced in some way. But not all treatments are the same, some treatments are industry accepted and won’t have a detrimental impact on the value of the stone where as some treatments will affect the value of the stone and should be avoided.
Fracture Filling with Natural Oils
As I mentioned above, natural Emeralds are usually quite heavily fractured and without treatment these fractures can easily spotted and they don’t look very nice. So to combat this they fill the fractures with natural oils such as cedar wood oil, this reduces the appearance of the fracture and makes the stone look more attractive.
This has been done for many years and is an industry accepted practise. You should take care with your Emerald if it has been fracture filled with oil as the oil can be removed over time and beauty and cleaning products can speed up the removal process.
Fracture Filling with a Coloured Dye
A process done to very poor quality Emeralds that have a combination of highly visible fractures and a poor body colour.
The issue with dying stones is that it is very easy to remove it from the stones, things such as cleaning and beauty products can soon draw the dye out of the stones. Even a being in a warm environment can cause this to happen.
A dyed Emerald should be considerably cheaper than an oil filled stone, due to the combination of poor quality material and significantly enhanced appearance.
Natural vs Synthetic
How the Emerald was formed has a big impact on the value of the stone, natural Emeralds will command a far higher price than a synthetic. This is because natural Emeralds are more desirable and the supply is also limited. A synthetic Emerald will be considerably cheaper.
One of the easiest ways to tell if an Emerald is natural or synthetic is to look at how free from inclusions the stone is, natural Emeralds are usually quite heavily fractured but synthetics are generally free from inclusions.
Origin
With natural Emeralds. the origin can have a big impact on the value. The most desirable location is Colombia as they have historically produced some of the world’s finest Emeralds but any stone from Colombia will attract a higher price per carat than the equivalent quality stone from anywhere else.
Emeralds are found in many other countries around the world but not many produce good, gem quality stones and until the recent discoveries in Zambia, Brazil produced the best quality Emeralds after Colombia.
Lab Reports
Laboratory reports are not as common amongst coloured gemstones as they are with diamonds but they can be a good source of information and if the company or person selling the Emerald claims that the stone has not been treated in anyway and/or claim it is from a certain location, then a report from a reputable gem lab, such as GIA, AGL, IGI, SSEF or Anchorcert is a must.
The majority of these labs have online report checkers so you can check to make sure the report is genuine. If the report is from a lab that you have never heard of, it is always worth doing a quick internet search to see if there are any reviews of these labs and how trustworthy their reports are.
Conclusion
As you can see, there are quite a few factors that affect the value of an Emerald and all of them should be taken into consideration when buying one.
A report from a reputable gem lab is always as useful tool to identify the above factors but having the opinion of an experienced gemmologist can also make the buying decision much easier.
Other articles from The Gem Guide series:
I'm Paul Haywood FGA DGA, a fully qualified Gemmologist and Diamond Grader from the Gemmological Association of Great Britain and a lover of all things jewellery.