Rotor blades, vibrational dampening elements, and methods are provided. A rotor blade includes a platform, a shank extending radially inward from the platform, and an airfoil extending radially outward from the platform. One or more fluid chambers are defined within the rotor blade. Glass is disposed within each fluid chamber of the one or more fluid chambers. A mass is disposed within each fluid chamber of the one or more fluid chambers. The mass is movable within the glass relative to the airfoil.