Geosamples (also known as SESAR) is a system for Earth sample registration that distributes the International Geo Sample Number IGSN. The System for Earth Sample Registration (SESAR) is a web-based registry that promotes sharing, linking, and integration of sample-based data by the assignment of IGSNs. The IGSN or International GeoSample Number is a 9-digit alphanumeric code that is assigned to specimens and related sampling features such as drill holes or wells to ensure their unique identification and unambiguous referencing of data generated by the study of samples. More than 4 million sites and samples have already been registered in SESAR.