        texture{ pigment{ color rgb<0.50,0.35,0.25> }
                 normal { radial poly_wave 3.5  frequency 18  
                          scale 3  turbulence 0.25 rotate<100,0,0> }
                 finish { phong 1 phong_size 10 reflection 0.01 }
               } // end of texture ------------------------------
