This U.S. industry comprises establishments primarily engaged in one or more of the following: (1) mining clay (except kaolin and ball), ceramic, or refractory minerals; (2) developing the mine site for clay, ceramic, or refractory minerals; and (3) beneficiating (i.e., preparing) clay (except kaolin and ball), ceramic, or refractory minerals. Illustrative Examples: Bentonite mining and/or beneficiating Fuller's earth mining and/or beneficiating Common clay mining and/or beneficiating Magnesite mining and/or beneficiating Feldspar mining and/or beneficiating Nepheline syenite mining and/or beneficiating Fire clay mining and/or beneficiating Shale (except oil shale) mining and/or beneficiating Cross-References. Establishments primarily engaged in--