Laboratory
National Gemstone Testing Center (NGTC)
Beijing, China
Gemstones, jade, diamonds, precious metals (national centre)
The National Gemstone Testing Center (NGTC) in Beijing is China's national laboratory for gems and precious metals, with branches across the country.
What it does
Testing and grading of gemstones, jade, diamonds and precious metals; NGTC reports are widely used in Chinese retail, and it works on Chinese national standards for jewellery.
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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