Walter Keller had a birthday party. And 300 clay mineralogists came to help him celebrate his 90th birthday. They stayed for the 27th annual meeting of the Clay Mineral Society, October 6–11, hosted by the Department of Geological Sciences, University of Missouri-Columbia. A short course, “Neutron Scattering Technology for Clay Mineral Investigation,” preceded the technical session.
The three important points that came out of the technical session were that inelastic scattering of neutrons yields information about the character and orientation of organic and water molecules in the interlayer space; that small-angle neutron scattering (SANS) gives information on the level of aggregation of clay-sized particles; and that Rictveld techniques are not yet applicable to deciphering clay mineral structures.