Emerald gemstones have been around and prized by people in various nations for millennia– going as far back as ancient Egypt. These beautifully-colored green gemstones are still used by many in the 21st century as the stone of choice on their rings, necklaces, crowns, etc.
You must know how to identify original emerald if you’re interested in getting one because like all other gemstones, there is no shortage of emerald lookalikes in the market.
Image Credit: Guangzhou Zhou Hengfu Jewelry
Methods of Identifying Raw Emerald
Because of how beloved emeralds are by many jewel lovers, some fakes can be confusing to the unsuspecting buyer. However, like other gemstones, there are characteristics unique to emeralds that you can use to your advantage in determining if the stone you have is an emerald or not.
You can personally carry out most of the methods explained below at home at little cost; however, it’s advisable not to lean on only one test but mix as many of them as you can to get a conclusive answer.
1. The Dye Test
Emeralds are made from the mineral called beryl; however, its green color is caused by trace amounts of chromium or vanadium in its formation. Without the trace elements of chromium or vanadium to color the beryl, jewelers would not classify the stone as emerald.
In cases where the “coloring elements” are absent or too little in the stone, what you have is called transparent or pale beryl.
To “fix” the issue of the stones not meeting up with the standard emerald color, some people treat them with dyes. Usually, emeralds are treated with colorless oil of a similar refractive index to emeralds to fill the inclusions and improve their clarity.
However, using dyes to treat the stone is a shady attempt to trick buyers into overpaying for a stone of little worth.
There are two ways to check if your stone is dyed:
- Using a magnification glass, turn the stone in different directions; if you notice that the stone is transparent in one of the angles, then it’s a dyed stone. Also, on some poorly-done dye works, you would observe the dye in the inclusions.
- Secondly, some emerald dyes do not react well with placed in water. Drop your stone in a clear glass of water; some dyed stones become transparent in the water while the dyed veins become very prominent. The beryl dying technique that produces this result is mostly found in India.
2. Check For Inclusions
About 99% of all natural emeralds have imperfections (called inclusions) within them that are a result of small bits of gasses, minerals, and liquids that are a part of their crystalization. The number of inclusions on an emerald is relatively higher than what you would get on other stones, making its clarity less than other gemstones.
The inclusions in an emerald can be obvious even to the naked eye; this extreme level of inclusion can reduce the emerald’s beauty and value. Also, most emeralds are treated to improve their clarity and reduce the visibility of the inclusions, so your naked eyes might not see them.
To properly check for inclusions, you would need a magnifying loupe to look within the stone; if it looks too perfect or inclusion-free, you are likely in possession of a fake.
However, makers of synthetic stones now purposely put inclusions when making their stones and it can be hard for an inexperienced person to know. To reduce your chances of making a mistake, you can read this guide to know what the inclusions in a raw emerald should be like.
3. Refraction Test
Every gem has a unique refractive index, which is the measurement of how light bends as it passes through the stone. If you want to perform a test of the stone’s refractive index, you can use a tool known as a refractometer.
To measure the refractive index, you should first put a little bit of the refraction oil on the transparent area and put the gem on it. Place your eyes on the eyepiece and you should see the result of the measurement.
The refractive index of natural emeralds is between 1.565 and 1.602, while synthetics have a range of 1.561 and 1.564; if the results you get are outside this range, it’s likely a fake stone.
4. Fluorescence Test
You can check the stone to know if it’s an emerald by testing its fluorescence; different gemstones have varying fluorescence, and this can be tested using an ultraviolet flashlight.
To perform a fluorescence test, put your stone in a dark room and point the flashlight at the stone to see what color it reflects. If the stone has no fluorescence, it is likely a natural gemstone while synthetic emeralds mostly produce a bright red, olive-green, or yellow fluorescence.
There are some synthetic emeralds with no fluorescence and some natural ones have red or orange-red fluorescence.
The ultraviolet test is not a reliable one on its own because there are different contradicting results you could get for various stones. Also, some other gems have the same fluorescent characteristics as a raw emerald and this can make your tests inconclusive or confusing.
5. Density
Every material on earth has a unique density and using this technique, you can find out if your stone is an emerald. The density of emerald is 2.6-2.9 g/cm3, and anything that has a density that’s less than or above that range is not an emerald stone.
You need two major pieces of equipment to measure the stone’s density:
- A water container that has measurement in milliliters
- A scale that weighs in grams; the most reliable are electric scales.
With these materials at hand, the steps you are to take are as follows:
Step 1– Measure the weight of the stone using the scale.
Step 2– Record how much water is in your container.
Step 3– Carefully place the stone into the container of water and avoid any spills. Wait till the water is fully settled again and record the new quantity.
Step 4– Subtract the original water quantity from the new measurement.
Step 5– Divide the weight of the stone by the result you got above; the result you get is the density of the stone.
The formula for measuring the density is therefore = Stone weight / (Quantity of water after – Quantity of water before). If the result you get is 2.6-2.9 g/cm3, the stone you have is likely an emerald.
6. Professional Certification
While you can try to test the authenticity of an emerald stone by yourself using the methods explained above, those methods are not foolproof. Manufacturers of fake gemstones are getting smarter and you might find yourself on the wrong end of a deal because of your inexperience in checking a stone’s authenticity.
The safest and most reliable way of finding out if your stone is a raw emerald is to have it professionally analyzed and certified. All good jewelers have their stones certified by reputable labs like the Gemological Institute of America (GIA). You should always ask them for this certificate before making any purchase.
A GIA certification would not only let you know if a stone is emerald or not; it provides an in-depth description of the stone. The certificate would indicate if the stone is natural, treated, its origin, and many other important details.
If you’re trying to find out the authenticity of a little piece of emerald, then you can use the other methods above. However, when the stone is potentially worth hundreds of dollars and above, it’s best to leave the examination to the professionals.