Dolphin rings: This models created in Zbrush and has a polygonal geometry :

Model geometry is mesh(polygonal),this is not a Rhinoceros Nurbs geometry,its just imported into rhino 3dm file:

Sl file is cleaned in Materalise Magics (22-version) and ready for ptinting

1. ring parametersVolume = 492.733516 (+/- 1e-07) cubic millimetersRing size -17mm : 53-EURO: 6.5-USA
   Metal weights: Gold 14ky-6.3 grams Gold 18ky-7.6 grams Silver 925-5.1 grams

2. ring paramatersVolume = 929.507908 (+/- 1e-07) cubic millimetersRing size -21mm : 66-EURO: 11.5-USAMetal weights: Gold 14ky-12 grams Gold 18ky-14.3 grams Silver 925-9.6 grams