Authenticity and treatment disclosure policy
Our commitment
JOHYA undertakes to offer only natural stones, whose authenticity, origin and any treatments are disclosed transparently, in accordance with:
- French decree no. 2002-65 of 14 January 2002 on the trade in gemstones and pearls
- The rules set by CIBJO (the World Jewellery Confederation)
- The standards of the independent gemological laboratories we work with
Origin of the stones
JOHYA sources directly in Colombia, mainly in the Muzo region (department of Boyacá), known for its exceptional emeralds. The traceability of each stone is documented from its purchase to its sale. The deposits are described on the Colombian emerald mines page.
Emerald treatments
Almost all emeralds sold worldwide undergo a treatment intended to improve the readability of the stone by reducing the visibility of natural inclusions. The most common treatment is impregnation with oil (cedar oil) or resin.
The laboratory measures two distinct things. The nature of the filling product, oil or resin. And its quantity, expressed on the laboratories' scale: no treatment (no oil), insignificant, minor, moderate, significant. A minor grade says nothing about the nature of the product. Both pieces of information appear on each product page.
What the decree requires
Decree no. 2002-65 of 14 January 2002 distinguishes two situations. Impregnation with a colorless fluid substance falls under traditional lapidary practices and does not require the mention "treated" (article 3). Filling with solidified foreign materials visible under a 10x loupe does require the mention "treated" and an information sheet handed over before the sale (articles 2 and 4). We apply the mention "treated" to any stone whose report indicates a solidified filling, and we disclose the treatment in every case, including when the exemption applies.
Gemological certificates
Every stone offered for sale comes with a certificate issued by an independent gemological laboratory. The report states the weight in carats, the dimensions, the color, the clarity, the geographical origin when attested, and the treatment detected.
We work with several independent laboratories, in France and abroad, depending on the stone and the level of analysis required. The name of the laboratory and the report number appear on each stone's product page, and the verify my stone page finds a stone's file from its number.
Authenticity guarantee
JOHYA guarantees that each stone sold matches the description on its product page. In case of dispute, the Customer may have a counter-analysis carried out by a recognized independent laboratory. If the analysis confirms a substantial non-conformity of the stone with the description, JOHYA will refund in full, including appraisal and return costs, within the limits of what is strictly necessary to establish the non-conformity.
Care and storage
As emeralds are relatively fragile stones, sensitive to knocks, solvents and sudden temperature changes, it is recommended:
- To remove them before any manual work, sport, or contact with chemicals (perfumes, creams, household products)
- To clean them only with a soft, slightly damp cloth
- To avoid ultrasonic and steam cleaners, which can alter treatments
- To store them separately from other jewelry to avoid scratches
A new oil treatment can be carried out periodically by a professional to preserve the stone's brilliance.