Diamonds for investment are certified with identification documents, signed and issued by a laboratory after examining the stone: they are indicated in the identity, mass, shape and measures.

In the certificate of a stone they are highlighted for the document number, the type of stone identified with the analysis and, finally, the characteristics that it presents. Attestations relating to offer sufficient guarantees of reliability and impartiality because made by experts, technicians and especially by people not directly involved in the transaction itself.

Institutions that are internationally recognized are:

• GIA (Gemological Institute of America, New York)
• HRD (Hoge Raad voor Diamant, Antwerp)
• IGI (International Gemological Institute, Antwerp)
• EGL (European Gemological Laboratory, Antwerp)