A composition and associated methods for chemical mechanical planarization (or other polishing) are described. The composition may comprise an abrasive and a dispersed hybrid organic/inorganic particle. The composition may further comprise an alkyne compound. Two different methods for chemical mechanical planarization are disclosed. In one method (Method A), the CMP slurry composition employed in the method comprises comprise an abrasive and a dispersed hybrid organic/inorganic particle. In another method (Method B), the CMP slurry composition employed in the method comprises comprise an abrasive and an alkyne compound. The composition may further comprise an oxidizing agent in which case the composition is particularly useful in conjunction with the associated methods (A and B) for metal CMP applications (e.g., tungsten CMP).