Mokume is a combination of metals, in this case sterling silver and copper, which are layered together and then sliced in a way to give the look of wood grain in metal. 

Julie buys Mokume in flat sheets and then creates jewelry from it. On this ring, she made a ring from sterling silver, then cut the Mokume into a wavy pattern and put the Mokume ring on top of the sterling ring.

The she put a little melee diamond for some sparkle.

NOTE: this ring cannot be sized, but Julie is willing to make one just for you in the correct size if need be. :-)