Brilliant finish cymbals are machine buffed and then hand polished to a smooth, bright, and shiny look. Natural finish cymbals are neither buffed nor polished, remaining instead in their natural state. The sound between Natural and Brilliant cymbals differs only slightly. The slight tonal difference is created by the smoothing of the grooves created by the lathing process. The sound vibrations move through the grooves from the low valleys to the high peaks: the smoothing of those peaks results in a slightly smoother, “glassier” sound.
-Republished with permission from Sabian.com

Brilliant Natural