238. The revocation does not apply to sand, gravel, building-stone and stone used for sculpture, limestone, calcite used as flux, millstones and grindstones, gypsum, common clay used in making building materials, firebrick, pottery, ceramic substances, mineral waters, infusory earths or tripoli, fuller’s earth, peat, marl, ochre or soapstone.
1965 (1st sess.), c. 34, s. 210; 1982, c. 27, s. 8; 1982, c. 58, s. 46.