Latest News

G-Probe Round 24 – Deadline extended owing to circumstances associated with Covid-19

The Round 24 test material has beeen dispatched. Only one test material – a basanite glass has been supplied for this round. Distribution of the speleothem carbonate pressed nano-powder pellet will be deferred until the next round, in spring 2021.

The system is now ready to accept your data for the basanite, BKWE-1G. The deadline for submission has been extended to 15th January on account of deliveries having been delayed and the uncertainty associated with renewed lockdowns due to Covid-19.

Note that owing to the exceptional circumstances of the Covid-19 pandemic, there will be only one round this year.

The G-Probe report for round Round 23, involving the Norite glass test material NoSM-1G, is available for download.

For enquiries about:

The test material and the G-Probe programme, contact Dieter Garbe-Schönberg: dieter.garbe-schoenberg@ifg.uni-kiel.de​

The delivery of test materials, contact Charles Gowing: cjbg@bgs.ac.uk

The website and reporting results online, contact Peter Webb: gprobe.iag@gmail.com

Payments and subscriptions, contact Chris Jackson: iag-treasurer@virginmedia.com

The G-Probe proficiency testing programme is provided by the International Association of Geoanalysts (IAG): www.geoanalyst.org/

The IAG gratefully acknowledges the major role that Steve Wilson (USGS) has played in initiating, organising and developing the G-Probe programme over many years.

G-Probe Account Number

Login ID



You are required to have authorisation from G-Probe before you proceed and you are strictly limited to the use set out within that authorisation. Unauthorised access to or misuse of this system is prohibited and constitutes an offence under the Computer Misuse Act (UK) 1990.
Your use of this website is subject to the terms and conditions of participation in G-Probe. By continuing you imply your acceptance of these terms and conditions.

Not yet a member?     About G-Probe    

If your contact details have changed please update them. If your contact status or that of your colleagues has changed please email us, quoting your G-Probe account number.

International Association of Geoanalysts - G-Probe

Version: 1.00a