Go Forward


The chemical laboratory at the COLS was established in 2011, and specializes in the geochemical and petrological analysis of obsidian. Our research staff include a petrologist, a geochemist, an archeologist and a geomorphologist, and we promote interdisciplinary collaboration between geological and archeological research. WDXRF, EDXRF, and PXRF analytical instruments are installed at the head office in Nagano, while those of XRD and SEM-EDS are installed at the branch office in Tokyo. In the future, we will integrate all instruments at our head office. 
The chemical laboratory accepts requests for the chemical analysis of rocks, minerals and obsidian by XRF and SEM-EDS. In addition to these, chemical analysis for the estimation of archeological obsidian sources is also available at the branch office in Tokyo. Please contact us for pricing and sample submission details.

Research projects and activities

  1. Quantitative analysis of silicate rocks and obsidian by WDXRF
  2. Standardization of geochemical reference samples of obsidian
  3. Nondestructive analysis of obsidian artifacts by XRFs
  4. Estimation of the source of archeological obsidian by the Mochizuki (1994) method
  5. Development of methods for the estimation of archeological obsidian sources

Laboratory Staff

  1. Dr. Yoshimitsu Suda (Petrologist, Geochemist): Manager at COLS head office, Nagano
  2. Mr. Taro Kannari (Archeologist): Manager at COLS branch office, Tokyo
  3. Mr. Kensuke Tsurumaki (Geomorphologist): Collaborator at COLS branch office, Tokyo
  4. Ms. Tomomi Minezaki: Assistant at COLS branch office, Tokyo

X-ray Instrumentation

  1. Wave Length-dispersive X-ray Spectroscopy (WDXRF): Rigaku PrimusIII+
  2. Energy-dispersive X-ray Spectroscopy (EDXRF); JEOL JSX-3100II
  3. Handheld X-ray Spectroscopy (PXRF): Element Tester DELTA Premium
  4. Energy-dispersive X-ray spectroscopy (SEM-EDS): JSM-6610LA

Appearance of XRFs at the head office in Nagano Appearance of SEM-EDS and XRD at the branch office in Tokyo


  1. Polarization microscope: Leica DM2500P, DFC295
  2. Diamond saw: Maruto MC-420; Struers Discoplan TS, Accutom 50
  3. Grinder: Maruto Power lap, Maruto lap, Dialap Ace
  4. Crushing machine: Fritsch P-1 Model II
  5. Automatic mortar: Ishikawa ABG type
  6. Digital scale: A&D GH-202
  7. Ultrapure Water Systems: Millipore Direct-Q UV
  8. Electric furnace: Thomas TMF-5, ETTAS EO-300B


1. Suda, Y. (2012) Chemical analysis of obsidian by Wave Length-dispersive X-ray Fluorescence Spectrometry: application to nondestructive analysis of archeological obsidian artifacts. Natural Resource Environment and Humans, no.2, 1-14.