This ring has five flat openings that resemble an open accordion.  The five sterling silver lines have a polished finish surface and the insides of those lines is oxidized.  The center line raises higher than the other four lines, giving this ring a sophisticated graduated structure.   This ring measures 20MM wide and 8.75MM tall. 
 
It is created using a process called lost wax process, or cire-perdue in French.  More than a ring, you're wearing a sculpture because that is what a wax cast mold creates.   
 
Superb skill and artistry translate to pure comfort.  Wax casting is not for everyone, only those with the skill and patience to make an individual mold for each individual ring.  A wax mold is hand-made, then the hot, liquid sterling silver is poured into it.  This process then melts away the mold, destroying it.  What is left is a sterling silver sculpture of the mold.  A new mold is then made to make another ring, and so on.
 
Common on every continent except Australia, the lost-wax method dates from the 3rd millennium BC and has sustained few changes since then.