This modern ring 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.   
 
The square top of this ring is accomplished by staggering four rectangle lines of sterling silver.  Each line is 14.8MM long.  The square top is 23MM wide by 20MM tall.  The four lines come together to taper to a 6.7MM back.
 
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.