Website: Address: 581 Fifth Avenue, New York, NY 10017 Phone: +1 (212) 207-4140 Gemological Science International is involved in the diamond grading industry and uses its advanced technology and laboratories to assess diamonds. This company is different from the rest because its proprietary software grades diamonds with reduced error. Gemological Science International offers lab services, grading reports, education, and research opportunities. After careful inspection in the labs, a GSI Certificate is made available and contains information on the clarity, cut grade, measurements, and other criteria. Gemological Science International strives to maintain its spot as a trusted leader in the diamond grading industry. Gemological Science International Facebook: Instagram: Twitter: ©