The rare earth metals, e.g., Sm, Gd, Dy, Ho, Er, and Yb including Y, were anodized in a 0.1N solution of reagent grade sodium metasilicate. A current density of 0.16 A/cm2 was employed in all reactions. The reaction cell was thermostated at . Dielectric breakdown (sparking) was observed with all of the metal‐electrolyte combinations investigated. The anodic spark reaction process produced coatings the components of which were derived from the anion constituent of the electrolyte. Orthosilicate coatings were produced on samarium and gadolinium metals and mixtures of orthosilicate and a distorted sesquioxide coating were produced on yttrium, dysprosium, holmium, erbium, and ytterbium metals. Powder x‐ray diffraction techniques were utilized to identify the anodic spark reaction products. Diffuse reflectance spectra between 200 and 700 mµ were also obtained for the anodic spark products. The reflectance spectra confirmed the results of the x‐ray diffraction study that single compounds exist in the anodic products for samarium and gadolinium metals and mixtures exist in the anodic products of yttrium, dysprosium, holmium, erbium, and ytterbium metals when these metals were anodized in sodium silicate solutions.