(a) Minerals are locatable if they meet the requirements in §3830.11 and are:

(1) Recognized as a mineral by the scientific community; and

(2) Found on Federal lands open to mineral entry.

(b) Under the Surface Resources Act, certain varieties of mineral materials are locatable if they are uncommon because they possess a distinct and special value. As provided in McClarty v. Secretary of the Interior, 408 F.2d 907 (9th Cir. 1969), we determine whether mineral materials have a distinct and special value by:

(1) Comparing the mineral deposit in question with other deposits of such minerals generally;

(2) Determining whether the mineral deposit in question has a unique physical property;

(3) Determining whether the unique property gives the deposit a distinct and special value;

(4) Determining whether, if the special value is for uses to which ordinary varieties of the mineral are put, the deposit has some distinct and special value for such use; and

(5) Determining whether the distinct and special value is reflected by the higher price that the material commands in the market place.

(c) Block pumice having one dimension of 2 or more inches is an uncommon variety of mineral material under the Surface Resources Act, and is subject to location under the mining laws.

(d) Limestone of chemical or metallurgical grade, or that is suitable for making cement, is subject to location under the mining laws.

(e) Gypsum suitable for the manufacture of wall board or plaster, or uses requiring a high state of purity, is subject to location under the mining laws.