Treatment disclosure

Treatment disclosure is the obligation to state, in writing and at the point of sale, every treatment a stone has received. Heat on a sapphire, oil or resin in an emerald, glass in a fissured ruby, diffusion, irradiation, dye: whatever was done, the invoice says so. "Natural" is not disclosure, because it only rules out synthetic origin, and a heated sapphire is still natural. Silence is not disclosure either. Proper practice puts the treatment on the listing and on the invoice, and backs both with a current laboratory report. CIBJO's Blue Books and AGTA's enhancement codes, N for none, H for heated, O for oiled, set the same duty out; the trade argues about wording, not the duty.

The reason is money. An unheated sapphire or a no-oil emerald carries its premium only because the treated stone beside it was sold as treated. Take the word off one invoice and every honest invoice in the room is worth less.

On a lab report

The report supplies the evidence. GIA writes "indications of heating" or "no indications of heating"; SSEF and Gübelin use the same construction, and for emerald they grade the filler from insignificant to significant. GRS prefers letter codes, H for heated and H(a) onwards where residues sit in the fissures. Diffusion, in which an element is added during heating, gets its own wording and is never folded into "heated" on an invoice. Read the treatment line before the origin line. Origin is the romance; treatment is the price.

On GemsVerified, disclosure is a condition of admission to the register. Every listing states its treatment, "none" is recorded as an explicit choice rather than an empty field, and a dealer's disclosure practice is one of the things verification checks. What has been done to this stone, and will you put it on the invoice with the report number beside it. That is the whole question.