What is the IGSN?
IGSN stands for International Geo Sample Number. The IGSN is an alphanumeric code that uniquely identifies samples taken from our natural environment (for example: rock specimens, water samples, sediment cores), as well as related sampling features (sites, stations, stratigraphic sections, etc.). IGSNs obtained from SESAR are 9 characters long. IGSNs obtained from allocating agents other than SESAR may have different syntax, but all are guaranteed to be globally unique via a central registry.
1) IGSN:HRV003M16 (Registered object: Malachite specimen from Angola, registered by the Mineralogical Museum of Harvard University)
2) IGSN:WHO000BC7 (Registered object: Dredge CHAIN35-2 St18 D18, registered by the Woods Hole Oceanographic Institution)
3) IGSN: IECUR0002 (Registered object: Metamorphic rock powder from Australia, registered by Curtin University)
Syntax for IGSNs from SESAR:
The IGSN is a “mostly unintelligent” identifier. For namespaces assigned after June 2014 (e.g. example #3 above), the first five characters of the IGSN represent a name space (a unique user code) that uniquely identifies the person or institution that registers the sample. The first two characters will be IE, followed by 3 characters of the registrant's choosing. The last 4 characters of the IGSN are a random string of alphanumeric characters (0-9, A-Z). The IGSN follows the syntax of the URN (Uniform Resource Name) which is composed of a ‘Namespace Identifier' (NID), a unique, short string, and the ‘Namespace Specific String’ (NSS).
The length of the IGSN has been limited to 9 characters to keep it short enough for use on sample labels and for inclusion in data tables of publications (the number of characters is similar to data, for example, Sr isotope data typically use a 8 character string such as 0.703456). The IGSN is long enough for large institutions such as repositories or museums to register large numbers of samples (with 10 numbers plus 26 letters for the 4 random characters after the user code, a total of 36^4 = 1,679,616 sample identifiers per namespace are available).
IGSN namespaces that were obtained before July 2014 may have three character namespaces followed by a random string of 6 alphanumeric characters (e.g. examples #1 and # 2 above). For more information see http://www.geosamples.org/news/namespacechanges.