(a) Fit with uniform crystallite size of synthetic goethite (98.11%). A small amount of halite (1.89%) was also present. Circles: observed pattern; solid thin line: calculated pattern; solid thick line: calculated pattern for goethite; lower gray line: difference curve. (b) Fit of synthetic goethite (goethite: 98.13%; halite: 1.87%) with the triaxial ellipsoid model. Symbols as in (a).