List of authorized laboratories for certification / grading of diamonds of 0.25 carat and above are given in paragraph 4.74 of Handbook of Procedures.
An exporter (with annual export turnover of Rs 5 crores for each of the last three years) or the authorized offices/agencies in India of laboratories mentioned under paragraph 4.74 of Hand Book of Procedures may export cut & polished diamonds (each of 0.25 carat or above) to any of the agencies/laboratories mentioned under paragraph 4.74 of Handbook of Procedures with re-import facility at zero duty within 3months from the date of export. Such facility of re-import at zero duty will be subject to guidelines issued by Central Board of Customs & Excise, Department of Revenue.