(57) A mineral breaker (10) including a pair of rotatable drums (14) each having radially projecting breaker teeth (16), the teeth on both drums being arranged in axially spaced groups (18) of circumferentially spaced teeth, the groups of teeth on one drum being axially offset from the groups of teeth on the other drum so that teeth in one group on one drum pass between neighbouring groups of teeth on the other drum, and a breaker bar (30) assembly located beneath the pair of drums and arranged to co-operate with the teeth on the drums so as to break oversized lumps of mineral passing between the drums, the breaker bar assembly including an elongate support member which extends longitudinally of the drums and on which a first and second series of laterally projecting breaker teeth are supported, the breaker teeth in each of said series of teeth being spaced from one another longitudinally of the support member to enable the groups of breaker teeth on a respective one of the drums to sweep therebetween.