(1) The gross value of minerals subject to tax will be determined at the point where mining processes end and manufacturing or non-mining processes begin.   In general, mining includes overburden removal, blasting, loading, transportation between mining processes, sorting, reduction and drying.   Processes which will be considered non-mining are fine grinding, burning or calcining, blending with other materials, and treatment effecting a chemical change and packaging.

(a) The points at which mining processes end for specific minerals are listed below:

 

Mineral                                                                                                Valuation Point

 

Bentonite                                                                                    after crushing and drying

Gypsum                                                                                      after crushing

Limestone                                                                                  after crushing

Talc                                                                                             after crushing and sorting

Vermiculite                                                                                 after screening

 

(b) No deductions will be allowed for processing costs incurred beyond the valuation point.