I still remember my first visit to a jeweler in Bangkok. The old craftsman, with calloused hands and a piercing gaze, showed me two emeralds that looked identical. "This one is worth €5,000, the other barely €50. Can you tell them apart?" he asked me with a mischievous smile. That impromptu lesson changed the way I saw these stones forever.
Emeralds have always captivated us. Their intense, almost mystical green has transcended time, retaining its power of attraction. Cleopatra adored them, maharajas coveted them, and even today, they inspire dreams. But beware: for every genuine emerald, how many fakes circulate on the market?
At Mayuri Paris, we work exclusively with Natural emeralds , primarily from Zambia, treated with oil according to tradition. If you prefer other origins such as Colombia or Brazil, we can source them upon request.
1. The "garden" - the natural signature of the emerald
My first instinct when examining an emerald? To take out my 10x loupe and look for what is affectionately called the "garden." These natural inclusions—small fractures, tiny needles, or trapped crystals—tell the stone's eventful story.
A perfectly clean emerald? Be wary! Nature isn't that perfect. I've seen customers disappointed to learn that their flawless "great deal" was actually a lab-grown imitation.
On the other hand, I learned to recognize artificial inclusions: bubbles that are too regular or linear structures that betray glass or synthetic materials.
2. The reaction to UV light – a revealing behavior
One evening, in a gemologist friend's workshop, we played around by illuminating different emeralds with his UV lamp. Surprise: the reactions were completely different depending on the origin!
The Colombian ones glowed with a faint reddish fluorescence, while those from Zambia remained almost inert. These subtle differences reveal much about their chemical composition and place of origin.
However, be aware that some synthetic materials also react to UV light, but often more intensely or uniformly.
3. The weight that doesn't lie
"Here, weigh these two stones," a merchant from Rajasthan once told me. The difference was striking: for the same volume, the natural emerald seemed lighter than the leaded glass imitation.
The density of a genuine emerald ranges from 2.7 to 2.9 g/cm³. This is a valuable indicator, especially for those accustomed to handling these stones. With a small container of water and a precision scale, you can even calculate this density at home.
4. The fog test - simplicity and effectiveness
I love showing this little trick to beginners: gently blow on the stone to create condensation. On a real emerald, the condensation disappears quickly because the thermal conductivity is good.
On some imitations, especially those made of glass, condensation lingers. It's not foolproof, but it gives you a general idea without needing any special equipment.
5. Hardness - resistant but brittle
With a hardness of 7.5 to 8 on the Mohs scale, emeralds are paradoxical: hard enough to scratch glass, yet fragile enough to shatter easily. This is why experienced cutters handle them with such care.
I strongly advise against scratch tests - too risky! But knowing that an emerald can be scratched by a sapphire or a ruby can be useful in certain situations.
6. Dichroism - when color changes depending on the angle
My first encounter with a dichroscope dates back to my studies. What a revelation! A natural emerald shows a subtle variation in color depending on the angle of observation: from yellow-green to blue-green.
Imitations lack this fascinating characteristic. It's as if the stone were telling you its crystalline story by changing color before your eyes.
7. The refractive index – the optical signature
True enthusiasts invest in a refractometer. The refractive index of an emerald is between 1.57 and 1.58. I've seen smartphone apps that, with a small accessory, allow you to estimate this index.
A higher index often indicates a glass imitation or a synthetic spinel. For me, checking this parameter on important gemstones has almost become second nature.
8. Treatments - the art of improvement
During a trip to Colombia, I visited traditional workshops where emeralds have been immersed in oil baths for generations. This age-old treatment, accepted by the market, enhances clarity without altering the stone's natural properties.
However, some modern treatments with resins or polymers leave me perplexed. These heavy-duty interventions create stones that are too "perfect," too shiny to be genuine.
At Mayuri, we favour natural emeralds with only the traditional oil treatment, never synthetic resins or aggressive processes.
Conclusion: Expertise remains irreplaceable
These tests have often saved me, but nothing replaces the trained eye of a professional. After years of handling these stones, certain details become obvious: the way light passes through the stone, its reaction to changes in lighting, its temperature to the touch...
If you're looking for a large emerald, choose jewelers who offer gemological certificates. If you have any doubts, don't hesitate to consult an independent expert or a specialized laboratory.
A genuine emerald tells a story millions of years old. It bears the marks of its turbulent formation, and that is precisely what makes it so priceless.
