6The material in Group 3 comprises only—
(a)moulding sands, including used foundry sand;
(b)clays, including moulding clays and clay absorbents (including Fuller’s earth and bentonite);
(c)mineral absorbents;
(d)man-made mineral fibres, including glass fibres;
(e)silica;
(f)mica;
(g)mineral abrasives.