This document discusses the challenges of inconsistent sample cataloguing practices and lack of online sample discovery. It introduces the International Geo Sample Number (IGSN) as a solution to provide globally unique identifiers for physical samples. It then describes the implementation of IGSN at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia, including developing an allocating agent service, description metadata schema, and sample registration system. Finally, it discusses applications of IGSN for sample tracking, discovery, and linking samples to related resources, and lessons learned from CSIRO's implementation.