Abstract: An automated gemstone sorting apparatus and method that handles, tests, and sorts a batch of irradiated topaz, or similar gemstones, in an efficient manner in accordance with residual radiation levels. The sorting apparatus and methods of the invention include a system of three parallel conveyors, i.e., input, accept and reject conveyors, as well as a vibrator bowl for automatically loading the gemstones in an orderly fashion onto the input conveyor. A multiplicity of isolated testing chambers is located to the side of the conveyor systems, each having a radiation detector and appropriate radiation measuring apparatus. Each of the isolated testing chambers has a single robot station associated therewith for manipulating the gemstones into and out of its respective testing chamber. Each robot station includes a pneumatic "puffer", responsive to a sensing device for directing a puff of air at a specified point on the input conveyor belt when a gemstone is sensed at the specified point.