Laboratory
GAAJ-ZENHOKYO Laboratory
Tokyo, Japan
Diamonds, coloured stones, pearls; origin reports
GAAJ-ZENHOKYO Laboratory is a Japanese gem laboratory formed by joining two of the country's established laboratories, with offices in Tokyo, Osaka and Kobe.
What it does
Diamond grading, coloured stone and pearl identification, and origin reports for the Japanese trade.
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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