Estimating the water content of hydrated minerals using reflectance spectroscopy II. Effects of particle size Ralph E. Milliken ∗ , John F. Mustard Department of Geological Sciences, Brown University, Box 1846, Providence, RI 02912, USA Received 21 July 2006; revised 30 November 2006 Available online 3 April 2007
Abstract Visible-near infrared reflectance spectra for five particle size fractions of a Hawaiian palagonite (HWMK101) and a nontronite (ferruginous smectite, Clay Minerals Society source clay SWa-1) were measured under ambient, purged, and heated conditions to characterize the effects of surface and volume scattering on the relationship between absolute H2 O content and the strength of the 3 µm absorption feature. Both materials were ground and dry sieved to particle sizes of
