Lately, With the progress of Cycles, different new metal materials have been published. This inspired me to these 3 rings.
Thanks for gold and silver go to elbrujodelatribu (http://www.blendswap.com/blends/view/38983 and http://www.blendswap.com/blends/view/69793), for platinum to BroadStu (http://www.blendswap.com/blends/view/48688).
Think of the ornaments as very thin ceramics. The 3 textures were made with GIMP. The rings have slightly different topology. As there are 3 ornaments combination can produce 9 different rings (That's why the rings and ornaments are still separated.) Also the number of the subs is freely eligible.
Rendertime for 1000 samples is 72min (on a notebook with win performance 4.7).