Section 20
SEC. 20. Lands of the fifth group shall be those which contain nonmetallic substances, such as: (a) Those used for building or construction purposes, such as marble, granite, clay, and the like. (b) Asbestos, feldspar, lime, mica, guano, phosphate, potash, saltpeter, niter, and the like. (c) Other substances used in the manufacture of paints, ceramics and fertilizers and for other industrial purposes.