Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         "Lapideum Regnum" nom. inval. - mineral kingdom
           Class "Petrae" - stones
             Order "Apyri" - stones unchanged by fire
               Genus "Talcum" - talc
                 "Talcum durum crassum, cortice nitido" - hornstone