We present measurements of the light-scattering phase function of selected carbon and ash particles in the geometric-optics regime in which the particle diameter is much larger than the wavelength of the light source. Measurements were performed on both single particles and particle ensembles. This was accomplished with two separate methodologies: an electrodynamic levitator for single-particle measurements and a particle feeder for the ensemble measurements. For each methodology, two irradiation sources were utilized: an argon-ion laser (lambda = 496 nm) and a xenon lamp. Results of the normalized phase functions are presented.