Laboratory
Gemological Science International (GSI)
New York, United States
Diamonds, lab-grown diamonds, gemstones
Gemological Science International (GSI), headquartered in New York, is a large gem laboratory serving retailers and manufacturers, with laboratories in several countries.
What it does
Diamond and laboratory-grown diamond grading, screening of melee for synthetics, coloured stone and jewellery reports, and research.
Using any laboratory
- Ask what the report will state (identity, treatment, origin, grade) and how long it takes; turnaround and fees change.
- Check a report online with the laboratory's own report-check service, and match the stone to the report.
- Reports from different laboratories can differ, especially on colour grades, treatment and origin. A report is an opinion based on the tests made, not a valuation.
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