Layman’s sample practice: geology for everyone
The layman’s sample practice of the Geological Survey of Finland (GTK) is a unique national practice in raw material exploration and research. Its primary purpose is to increase knowledge related to Finnish raw material resources. Therefore, the operation is quite rare on a global scale. A layman’s sample (kansannäyte) is a sample of rock, mineral, or soil sent to a geologist or other type of expert by a rock hobbyist. The Layman’s Sample Office of the Geological Survey of Finland (GTK) receives thousands of samples from all over Finland every year.
Figure 1: Logo of the layman’s sample practice of the Geological Survey of Finland (GTK)
The office handles ore samples, industrial minerals, dimensional stone, gemstone discoveries, and samples containing rare earth elements of technological interest. The concept of layman’s sample reflects the action of its history and original purpose. The practice started in the 18th century and has continued uninterrupted since then.
Figure 2 and 3: Checking the analysed rock samples in the field together with sample sender.
Figure 4: During the 20th century thirty-two of the metallic mines in Finland have been discovered based on a layman’s sample.
It provides competent and up-to-date information on the importance of raw materials to society and our everyday lives.
Therefore, the metal content of layman’s samples and metallogenic zones can be compared with each other so that potential ore targets can be identified. At its best, the extensive archive also reveals unexplored new areas.
Layman’s sample practice is an efficient and inexpensive ore and mineral prospecting method suitable for all glaciated areas and educational purposes. In addition, it is a valuable and healthy nature hobby for everyone.
Figure 5: Layman’s sample practice is a valuable and healthy nature hobby for everyone.
Jari Nenonen works as a geologist at the Geological Survey of Finland (GTK). He graduated as a geologist from the University of Turku with a specialization in quaternary geology. Jari is responsible for the Layman’s sample practice in GTK and in Finland. His main interests are layman’s samples, ore prospecting and quaternary geology. During his nearly 40-year career, Jari has worked on several different projects from quaternary geology and environmental geology to mineral exploration and geological popularization. He is a member of the European Geoparks Network and the UNESCO Global Geoparks network. In addition to his main work, he works also as a geologist at Rokua UNESCO Global Geopark.
Satu Hietala is a geologist (MSc) and a diploma gemologist (D.G.Fin, AJP, PCAA). She graduated as a geologist from the University of Helsinki with a specialization in bedrock geology and economic geology. Satu has been working at the Geological Survey of Finland (GTK) since 2011, where her primary task has been the mapping of mineral raw material resources and layman’s sample practice at the Mineral Economy Solutions unit. He graduated as a diploma gemmologist in 2016, organized by the Finnish Gemological Society. She also works as a teacher in mineralogy courses and since 2018 as a director of the gemological degree program. Satu is currently on study leave and is doing her PhD dissertation research at the University of Tartu in Estonia related to meteorite impact craters.
Tuomas Leskelä is a geologist (MSc) who graduated from the University of Turku with a specialization in bedrock geology. Tuomas has been working at the Geological Survey of Finland (GTK) since 2019, where his tasks have been the layman’s sample practice and geological 3D-modelling in the Mineral Economy Solutions unit.
Disclaimer: This article expresses the personal opinions of the author. These opinions may not reflect the official position of the European Federation of Geologists (EFG).