The Johya House
Our Method
Buy in person, double-check, and always certify. Here's how each stone makes its way to you.
My name is Vincent Renault, and I am a certified gemologist. Together with my business partner, Dimitri Velasco, we founded Johya based on a firm belief: the only way to guarantee the quality of an emerald is to select it yourself. Every stone in our catalog has been purchased by us personally, in person, through direct contact in the Boyacá region. This page describes what happens between that moment and the time the stone arrives at your doorstep.
Vincent Renault, certified gemologist and co-founder of Johya
Selection at the source
We source our stones directly from Colombia, in Bogotá and the Muzo region. No lots are negotiated remotely, and no photos are sent by a broker: each emerald is examined in person, in both daylight and shade, before any decision is made. We select a stone for its color, its inner life, and its potential, and we reject the vast majority of what is presented to us.
Independent Gemological Appraisal
Both on-site and upon return, each stone undergoes a series of tests before any decision is made to purchase or list it for sale. The degree of oiling is determined according to the laboratories’ scale—ranging from none to moderate—and is listed exactly as such on the description sheet. Nothing is concealed.
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10x Magnifying Glass
Examining the inclusions and looking for the "flash" effect, the first indication of a resin fill.
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365 nm UV Lamp
A wavelength that is more effective than standard lamps at detecting treatment residues.
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Routine Weighing
The weight is recorded at every stage between purchase and cutting: this is the cornerstone of our traceability system.
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Controlled Light
The high-altitude sun makes colors appear more vivid: a stone is also judged by its shadow.
Certification by a recognized laboratory
Every stone intended for sale is sent to an independent laboratory in Bogotá or Europe—GIA, CDTEC, or Gübelin, depending on the stone. The report certifies the stone’s natural origin, its Colombian origin, and the extent of any treatment. It accompanies the stone upon delivery, and its number appears on the product sheet.
One stone, one file
Every Johya emerald has a unique reference number. Its weight is recorded at every stage, from the rough stone to the finished gem: this is the thread that connects the stone in your jewelry box to the one we selected in Colombia. Identified seller, dated inspections, numbered certificate: the complete file for your stone is available upon request.
Our Commitments
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No resin ever
There are no resin-treated stones in the catalog. Traditional oiling is permitted, and the degree of oiling is always disclosed, even when regulations do not require it.
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Real photos
The photos and videos in our product listings show the exact stone you will receive. No computer-generated images, no color retouching.
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A Proven Origin, Not Just a Story
We only claim a specific mine of origin if a laboratory can verify it. Otherwise, the product description lists the origin as Colombia, which is the only verifiable information.
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The price of the stone, not the chain
Buying directly cuts out the middlemen. What you pay covers the cost of the gemstone, its inspection, and its certification.