Metale in industrie, 20 bucati Colectia contine 20 metale diferite obtinute industrial ca elemente chimice: magneziu, aluminiu, siliciu, titan, crom, mangan, fier, cobalt, nichel, cupru, zinc, molibden, argint, cositor, teluriu, bismut, ceriu, antimoniu, plumb, tungsten.