The Gemological Certification Laboratory (GCL) opened its doors for business in New York City in August. The lab’s diamond grading certificates are guaranteed to within a maximum one-grade tolerance as measured against the Gemological Institute of America’s grading system. In other words, if a consumer has a GIA Gem Trade Laboratory report that reveals a GCL certificate is more than one grade lower in color or clarity than what is certified, GCL will replace the diamond with one reflecting data on its initial certificate. The replacement diamond will be accompanied by a new GIA/GTL report.

GCL’s diamond grading reports also can include an appraisal/estimated replacement value.

GCL certified diamonds are laser-inscribed on the girdle edge with the certification number, which is shown in an enlarged photograph on the cert and an accompanying Diamond Data Card, a plastic credit-card-size version of the grading report that can be carried in the wallet. Gemological Certification Laboratory, 580 Fifth Ave., Lower Lobby, New York, NY 10036; (212) 398-4102, fax (212) 398-4054, e-mail:

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