<p>"Your <a href="https://mayuri-paris.com/collections/emerald">emerald</a> has been treated with oil." This sentence comes up constantly in my conversations with gemstone enthusiasts. And almost every time, I can sense a hint of worry in their messages. Yet there is really no reason to be alarmed.<br><br>
Oil treatment of emeralds has existed for thousands of years. Our grandmothers were already wearing oiled emeralds without knowing it. This technique, far from being a modern trick, is an integral part of traditional jewellery craftsmanship.<br><br>
So why does this confusion persist? Quite simply because the industry sometimes lacks transparency. At Mayuri, we have chosen the opposite approach: to explain exactly what lies behind this mysterious term.</p>
<h2>The "garden" of the emerald: why emeralds need a little helping hand</h2>
<p>Look closely at an emerald. Do you see those fine lines running through it? Those inclusions that are poetically called the "garden"? That is the raw beauty of the emerald.<br><br>
Unlike a diamond, which can be perfectly pure, an emerald is born with character. Its chaotic geological formation gives it these natural fissures. An emerald without a garden is like a face without expression: technically perfect, but strangely empty.<br><br>
The problem arises when these fissures reach the surface. Imagine a slightly cracked window: light no longer passes through it properly. The emerald then loses some of its natural brilliance.<br><br>
I have held magnificent Colombian emeralds in my hands that looked dull because of these micro-fissures. After treatment, they revealed a dazzling green colour. The stone itself had not changed: we had simply released its imprisoned beauty.<br><br>
That is exactly the role of oil treatment: <strong>to fill these tiny gaps so that light can circulate freely</strong>. Nothing more, nothing less.</p>
<h2>When Cleopatra meets the Colombian masters</h2>
<p>The history of emerald treatment has always fascinated me. Imagine that <strong>Cleopatra was already using oiling techniques</strong>! The Egyptians understood that a drop of oil could transform an ordinary stone into a royal jewel.<br><br>
On the other side of the Atlantic, pre-Columbian civilizations were developing their own methods. The Muisca, those legendary goldsmiths of Colombia, mastered to perfection the art of enhancing their sacred emeralds with plant resins.<br><br>
In the Middle Ages, Parisian lapidaries perfected these techniques. They discovered that cedar oil offered remarkable stability. This tradition has been passed down from workshop to workshop right up to the present day.<br><br>
<strong>At Mayuri, we work with natural emeralds treated with oil according to these ancestral traditions.</strong></p>
<h2>Workshop secrets: how it really works</h2>
<p>Let me take you behind the scenes. The oil-treatment process is not magical, but it does require precise know-how.<br><br>
First, the emerald is meticulously cleaned. Every trace of dust or old oil has to disappear. It is a bit like preparing a canvas before painting.<br><br>
Then comes the oil bath. We mainly use cedar oil, sometimes enriched with jojoba oil. The stone rests gently in this bath, sometimes for several days. Some colleagues use vacuum chambers to speed up penetration; we prefer patience.<br><br>
Temperature plays a crucial role. Too hot and the oil can alter the colour. Too cold and it will not penetrate deeply enough. Every emerald has its own temperament.<br><br>
The most delicate moment? The final cleaning. You need to remove any excess oil without damaging the treatment that has just settled into the fissures. One brusque movement can ruin hours of work.</p>
<h2>Traditional oil vs. modern resins: the battle of the century</h2>
<p>The modern industry now offers alternatives to traditional treatment. Synthetic resins, particularly those hardening polymers, promise superior durability.<br><br>
Personally, I remain sceptical. These resins polymerise permanently inside the stone. <strong>Once hardened, there is no going back</strong>. The emerald loses its natural “breathing”.<br><br>
The “ExCel” treatment is all the rage at the moment. Technically impressive, I admit. But philosophically? It turns the emerald into an artificial composite.<br><br>
<strong>We remain faithful to traditional oils</strong>. Why? Because they respect the stone’s natural cycle. An emerald can be re-oiled when needed. It keeps its capacity to evolve, like a living being.<br><br>
I have seen century-old emeralds still looking magnificent thanks to this principle. Their successive owners had simply maintained the treatment over the decades.</p>
<h2>The truth about prices (without sugar-coating)</h2>
<p>Let’s be frank: an oil-treated emerald costs less than an equivalent untreated stone. The difference? Somewhere between 10% and 30%, depending on the degree of treatment.<br><br>
This economic reality reflects rarity. A naturally clean emerald remains exceptional. But beware of shortcuts: a beautiful treated emerald is far preferable to a “natural” stone of mediocre quality.<br><br>
I recently offered a client two options: an untreated emerald at €8,000 with many visible inclusions, or a beautifully oiled stone at €5,500 with a flawless appearance. She chose the second without hesitation.<br><br>
The treatment also affects gemmological grading. A “lightly oiled” stone keeps a high value. A “heavily treated” emerald will be assessed differently. This nuance matters enormously when buying.<br><br>
Transparent pricing allows everyone to choose according to their priorities. Immediate beauty or absolute rarity? Both approaches are perfectly valid.</p>
<h2>The ethics of the trade: what everyone should know</h2>
<p>The gemstone industry has its rules. Any serious seller must disclose the treatments detected on a stone. This legal obligation protects buyers.<br><br>
Certificates from the major laboratories (GIA, SSEF, LFG) systematically mention this information. A certificate with no treatment listed guarantees a natural stone.<br><br>
But here is the crucial point: oil treatment is universally accepted within the profession. It is not “cheating”, but a legitimate traditional enhancement.<br><br>
<strong>An emerald oiled according to these ancestral techniques is therefore officially considered natural.</strong><br><br>
This professional consensus clearly distinguishes oiling from more controversial treatments such as artificial irradiation or thermal diffusion.</p>
<h2>Caring for your oiled emerald (without stress)</h2>
<p>Your treated emeralds require a few simple precautions. Nothing dramatic, just common sense:</p>
<ol>
<li><strong>Avoid extreme temperatures.</strong> A very hot bath or an intense sauna can cause the treatment oil to evaporate. Your jewels prefer the gentle warmth of your skin.</li>
<li><strong>Beware of harsh chemicals.</strong> Bleach and other household solvents attack the oil. Remove your rings before cleaning.</li>
<li><strong>Forget ultrasonic cleaning.</strong> These vibrations dislodge the oil from the fissures. Opt instead for gentle cleaning with warm soapy water.</li>
<li><strong>Plan for professional maintenance.</strong> Every 5 to 10 years, depending on how you wear your jewellery, it is possible to have the stone re-oiled. This procedure, carried out by a professional, restores your emeralds to their optimal brilliance.</li>
</ol>
<h2>Recognising a treated emerald: the little clues</h2>
<p>A few simple observations can reveal oil treatment. Look at your stone under different lighting conditions. Treated areas sometimes display subtle “oily” reflections.<br><br>
An average-quality emerald with no visible inclusions at all? Suspicious. Nature rarely produces perfect stones at that price level.<br><br>
Raking light often reveals tell-tale signs. The oil creates characteristic light interference in the filled fissures.<br><br>
But let’s stay humble: only a trained gemmologist with proper equipment can confirm the presence of treatment with certainty. Microscopic examination and spectroscopy never lie.<br><br>
If in doubt, do not hesitate to consult an expert. It will save you many unpleasant surprises.</p>
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<div class="emerald-guide">
<div class="container">
<div class="header">
<h2>Comparative Guide to Emerald Treatments</h2>
<p>Everything you need to know about the different enhancement methods for emeralds</p>
</div>
<!-- DESKTOP TABLE COMPLETE -->
<div class="desktop-table">
<table>
<thead>
<tr>
<th>Type of Treatment</th>
<th>Description & Method</th>
<th>Durability</th>
<th>Impact on Price</th>
<th>Industry Acceptance</th>
<th>Pros / Cons</th>
<th>Reversibility</th>
</tr>
</thead>
<tbody>
<tr style="background: #f0f8ff; border: 2px solid #2D5A6B; box-shadow: 0 4px 12px rgba(45,90,107,.08);">
<td>
<strong style="color: #2d5a6b;">Traditional Oiling ⭐</strong><br><em>Cedar oil, jojoba</em>
</td>
<td>Immersion in transparent natural oils (capillary action into open fissures). An ancestral method.</td>
<td>Optimal (85%)<br><small><strong>Protection + beauty revealed</strong></small></td>
<td>
<strong>-10% to -20%</strong><br><small>vs. untreated stone</small>
</td>
<td>
<span class="status-badge accepted">Universally Accepted</span><br>
<span title="Mayuri selection" class="choice-tag"><span class="star">⭐</span> MAYURI CHOICE</span>
</td>
<td>✅ Balance between beauty and strength<br>✅ Reveals beauty and protects the stone<br>✅ Millennia-old, respectful tradition<br>❌ Simple maintenance every 5–10 years</td>
<td>✅ YES<br><small>Re-oiling possible</small></td>
</tr>
<tr>
<td>
<strong>Synthetic Resins</strong><br><em>Hardening polymers</em>
</td>
<td>Artificial resins that polymerise (UV/chemical reaction) to fill fissures.</td>
<td>Very high (90%)<br><small>Permanent</small></td>
<td><strong>-15% to -25%</strong></td>
<td><span class="status-badge controversial">Accepted with Reservations</span></td>
<td>✅ Exceptional durability<br>❌ Alters the nature of the stone<br>❌ Loss of natural “breathing”</td>
<td>❌ NO<br><small>Irreversible</small></td>
</tr>
<tr>
<td>
<strong>"ExCel" Treatment</strong><br><em>Advanced optical resin</em>
</td>
<td>High-tech resin with a refractive index close to that of emerald; controlled polymerisation.</td>
<td>Excellent (95%)<br><small>Quasi-permanent</small></td>
<td><strong>-20% to -30%</strong></td>
<td><span class="status-badge controversial">Disclosure Required</span></td>
<td>✅ Perfect optical appearance<br>✅ Maximum stability<br>❌ Turns the stone into a composite<br>❌ Philosophically debatable</td>
<td>❌ NO</td>
</tr>
<tr>
<td>
<strong>Thermal Diffusion</strong><br><em>Heat-based modification</em>
</td>
<td>Very high-temperature heating with chemical elements; changes surface structure & colour.</td>
<td>Variable (40%)<br><small>Can degrade over time</small></td>
<td><strong>-50% to -70%</strong></td>
<td><span class="status-badge rejected">Highly Controversial</span></td>
<td>✅ Visible colour improvement<br>❌ Deep structural alteration<br>❌ Possible weakening<br>❌ Ethically questionable</td>
<td>❌ NO</td>
</tr>
<tr>
<td>
<strong>Irradiation</strong><br><em>Radioactive bombardment</em>
</td>
<td>Gamma or neutron radiation used to intensify the green colour.</td>
<td>Medium (60%)<br><small>Colour may fade</small></td>
<td><strong>-40% to -60%</strong></td>
<td><span class="status-badge rejected">Generally Rejected</span></td>
<td>✅ Intense, artificial colour<br>❌ Potential radioactive risks<br>❌ Non-natural colour<br>❌ Hard to detect</td>
<td>❌ NO<br><small>Atomic-level modification</small></td>
</tr>
<tr>
<td>
<strong>Natural Emerald</strong><br><em>No treatment</em>
</td>
<td>Stone in its natural state, only cut and polished; inclusions and fissures are accepted.</td>
<td>Fragile (45%)<br><small><strong>Open fissures = fragility</strong></small></td>
<td>
<strong>Reference price</strong><br><small>Maximum value but higher risk</small>
</td>
<td><span class="status-badge controversial">Rare but Risky</span></td>
<td>✅ Absolute authenticity<br>✅ Collector value<br>❌ Extremely fragile<br>❌ Higher risk in everyday wear<br>❌ Extremely rare</td>
<td>✅ N/A<br><small>Natural state</small></td>
</tr>
</tbody>
</table>
</div>
<!-- MOBILE CARDS COMPLETE -->
<div class="mobile-cards">
<!-- Traditional Oiling (MAYURI CHOICE) -->
<div class="treatment-card featured">
<div class="card-header">
<div class="card-title">Traditional Oiling</div>
<div class="card-subtitle">Cedar oil, jojoba</div>
<div class="mayuri-badge">
<span class="star">⭐</span> MAYURI CHOICE
</div>
</div>
<div class="card-content">
<div class="section-title">Description</div>
<p>Immersion in transparent natural oils. Penetration by capillary action into open fissures. An ancestral method.</p>
<div class="section-title">Durability</div>
<p>Optimal (85%) — <strong>protection + beauty revealed</strong></p>
<div class="section-title">Impact on Price</div>
<p>-10% to -20% vs. untreated stone</p>
<div class="section-title">Acceptance</div>
<span class="status-badge accepted">Universally Accepted</span>
<div class="section-title">Pros / Cons</div>
<p class="pros">Balanced beauty and strength; protects the stone</p>
<p class="pros">Respects a millennia-old tradition</p>
<p class="cons">Requires simple maintenance every 5–10 years</p>
<div class="section-title">Reversibility</div>
<p>✅ YES — re-oiling possible</p>
</div>
</div>
<!-- Synthetic Resins -->
<div class="treatment-card">
<div class="card-header">
<div class="card-title">Synthetic Resins</div>
<div class="card-subtitle">Hardening polymers</div>
</div>
<div class="card-content">
<div class="section-title">Description</div>
<p>Application of artificial resins that polymerise (UV/chemical reaction) inside the fissures.</p>
<div class="section-title">Durability</div>
<p>Very high (90%) — permanent</p>
<div class="section-title">Impact on Price</div>
<p>-15% to -25% vs. untreated stone</p>
<div class="section-title">Acceptance</div>
<span class="status-badge controversial">Accepted with Reservations</span>
<div class="section-title">Pros / Cons</div>
<p class="pros">Exceptional durability</p>
<p class="cons">Alters the nature of the stone; loss of natural “breathing”</p>
<div class="section-title">Reversibility</div>
<p>❌ NO — irreversible</p>
</div>
</div>
<!-- ExCel Treatment -->
<div class="treatment-card">
<div class="card-header">
<div class="card-title">"ExCel" Treatment</div>
<div class="card-subtitle">Advanced optical resin</div>
</div>
<div class="card-content">
<div class="section-title">Description</div>
<p>High-tech resin with a refractive index close to that of emerald; controlled polymerisation.</p>
<div class="section-title">Durability</div>
<p>Excellent (95%) — quasi-permanent</p>
<div class="section-title">Impact on Price</div>
<p>-20% to -30% vs. untreated stone</p>
<div class="section-title">Acceptance</div>
<span class="status-badge controversial">Disclosure Required</span>
<div class="section-title">Pros / Cons</div>
<p class="pros">Perfect optical look; maximum stability</p>
<p class="cons">Turns the stone into a composite; philosophically debatable</p>
<div class="section-title">Reversibility</div>
<p>❌ NO</p>
</div>
</div>
<!-- Thermal Diffusion -->
<div class="treatment-card">
<div class="card-header">
<div class="card-title">Thermal Diffusion</div>
<div class="card-subtitle">Heat-based modification</div>
</div>
<div class="card-content">
<div class="section-title">Description</div>
<p>High-temperature heating with added chemical elements: modifies colour and structure.</p>
<div class="section-title">Durability</div>
<p>Variable (40%) — can degrade over time</p>
<div class="section-title">Impact on Price</div>
<p>-50% to -70% vs. untreated stone</p>
<div class="section-title">Acceptance</div>
<span class="status-badge rejected">Highly Controversial</span>
<div class="section-title">Pros / Cons</div>
<p class="pros">Significant colour improvement</p>
<p class="cons">Deep structural alteration; possible weakening; ethically questionable</p>
<div class="section-title">Reversibility</div>
<p>❌ NO — permanent modification</p>
</div>
</div>
<!-- Irradiation -->
<div class="treatment-card">
<div class="card-header">
<div class="card-title">Irradiation</div>
<div class="card-subtitle">Radioactive bombardment</div>
</div>
<div class="card-content">
<div class="section-title">Description</div>
<p>Gamma or neutron radiation used to intensify the green colour.</p>
<div class="section-title">Durability</div>
<p>Medium (60%) — may fade over time</p>
<div class="section-title">Impact on Price</div>
<p>-40% to -60% vs. untreated stone</p>
<div class="section-title">Acceptance</div>
<span class="status-badge rejected">Generally Rejected</span>
<div class="section-title">Pros / Cons</div>
<p class="cons">Non-natural colour; potential radioactive risks; difficult to detect</p>
<div class="section-title">Reversibility</div>
<p>❌ NO — atomic-level modification</p>
</div>
</div>
<!-- Natural Emerald -->
<div class="treatment-card">
<div class="card-header">
<div class="card-title">Natural Emerald</div>
<div class="card-subtitle">No treatment</div>
</div>
<div class="card-content">
<div class="section-title">Description</div>
<p>Stone in its natural state (cut and polished only). Inclusions and fissures are visible and accepted.</p>
<div class="section-title">Durability</div>
<p>Fragile (45%) — open fissures mean increased fragility</p>
<div class="section-title">Impact on Price</div>
<p>Reference price — maximum value but higher risk</p>
<div class="section-title">Acceptance</div>
<span class="status-badge controversial">Rare but Risky</span>
<div class="section-title">Pros / Cons</div>
<p class="pros">Absolute authenticity; collector value</p>
<p class="cons">Extremely fragile; higher risk in daily wear; extremely rare</p>
<div class="section-title">Reversibility</div>
<p>✅ N/A — natural state</p>
</div>
</div>
</div>
</div>
</div>
<h2>When East meets West</h2>
<p>In Jaipur, I discovered fascinating oiling techniques. Indian dealers use blends of oils prepared according to ancestral recipes. Each family jealously guards its secrets: proportions of sesame oil, mustard oil, or local plant extracts.<br><br>
This intuitive approach contrasts beautifully with the scientific precision of Parisian workshops. In France, we measure, weigh, and time every step. Temperature control to the nearest degree, immersion time calculated according to the stone’s porosity, spectroscopic analyses to check how well the oil has penetrated.</p>
<h2>Conclusion: is oil treatment good for emeralds?</h2>
<p><strong>An oil-treated emerald is neither fake nor second-rate. It is a natural stone elevated by ancestral know-how.</strong><br><br>
To make a sound choice, always prioritise transparency. A seller should be able to tell you clearly whether an emerald has been treated and how.<br><br>
The future will probably bring new innovations: even more stable plant oils, more precise application techniques. The essential point, however, will remain unchanged: revealing natural beauty without betraying authenticity.</p>