Journal

Which gem lab report to ask for, and when

Guide · · Maedot

For a cut emerald, start with an identification report that names any treatment, including how much filler is in the fissures. Add an origin opinion when origin will move the price, as it can for emerald, ruby and sapphire. GIA and SSEF report on polished stones, so judge rough on inspection and test the stones after cutting.

What a report can tell you

  • Identification. What the stone is, whether it is natural or laboratory-grown, and any treatment the laboratory can detect. For emerald this includes the degree of clarity enhancement.
  • Origin. Where the stone most likely formed. It is an opinion, and laboratories can disagree or decline to give one.
  • Quality. Some laboratories add a colour type or a rating.

The Laboratory Manual Harmonisation Committee (LMHC), which aligns report wording among seven laboratories including GIA, Gübelin and SSEF, says a report should state that its findings are the laboratory's opinions and do not reflect value. It also notes that some treatments in other gems cannot yet be detected.

The laboratories

GIA, a nonprofit founded in 1931, publishes Gems & Gemology. It offers a Colored Stone Identification Report and an Identification & Origin Report, with origin available for emerald. Its US fee schedule from 1 July 2026 charges $75 and $90 respectively for a stone under 2 carats, and $50 more to identify an emerald's filler. For parcels of loose cut stones, a batch test for the level of clarity enhancement costs $120 for up to ten stones.

Gübelin Gem Lab, founded in 1923, has laboratories in Lucerne, Hong Kong, Bangkok and New York. Its full report covers identity, treatment and origin. Its Gem Passport, for faceted emeralds, rubies and blue sapphires up to 3 carats, is CHF 200 with origin or CHF 150 without, and says only whether an emerald is clarity-enhanced, not how much. In 2017 Gübelin introduced an Emerald Paternity Test, which tags rough crystals at the mine with DNA-based nanoparticles.

SSEF, a non-profit foundation in Basel, has tested gems since 1972. Its emerald reports name the filler and its amount. Its price list charges CHF 375 for an identification report on an emerald under 2 carats, and CHF 750 with origin.

AGL, in New York since 1977, works on coloured stones and says it was the first US laboratory to issue origin reports. Its Prestige Report names fillers and adds a Stability Index for how well a treatment should hold up in wear.

GRS, founded by Adolf Peretti in 1996, is known for colour types such as "pigeon's blood" for ruby; its "Muzo green" type is given only to Colombian emerald.

AGL and GRS are not LMHC members, and their terms can differ: AGL's wording still includes "insignificant", a category Gübelin dropped in November 2025.

Rough or cut

SSEF says it does not issue reports for rough. GIA's coloured-stone reports are for polished stones, its batch services exclude rough, and for identifying rough it suggests asking a local university or museum. For rough, that leaves inspection in person, on video or through samples.

For cut stones, fees follow weight bands, not value, so they weigh more on small commercial goods. Gübelin positions its Gem Passport for small stones and stones of moderate value. For a fine emerald, ruby or sapphire, a full report with origin is usual; Gem-A noted in 2017 that such stones are typically sold with one.

Before you rely on a report, check that it matches the stone, and verify it online where the laboratory offers this, as SSEF and Gübelin do. Treat an old emerald report with care. In June 2026 SSEF warned that tested stones were being refilled and resold with their original reports.

At Maedot

Each selection lists the stated origin and any treatment or testing on record. If your market expects a particular laboratory's report, tell us when you ask about a stone.

Sources

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