Apparatus for sorting ore rocks in which rocks are fed in stream past detector to measure characteristic selected as basis for sorting and into free flight trajectory from which selected individual rocks are deflected according to measure of said characteristic for those rocks. Apparatus is characterized by rock feed means comprising pair of movable elements having surfaces defining upwardly facing nip and which move downwardly at nip to grip rocks and accelerate them downwardly into free flight such that the free flight trajectory is substantially vertical.The movable elements may be a pair of horizontal rollers having resiliently deformable peripheral surfaces or a pair of flexible endless belts arranged in loops having upper parts defining the nip and, below the nip, adjacent downwardly extending runs between which the rocks are gripped and moved downwardly for some distance below the nip before being projected into vertical free flight.