These Coaster Sets (which include 4 coasters) are made from black walnut and epoxy resin.  In each set, the river flows from coaster to coaster (see images).  We have the awesome blend of blue and purple as well as the red with an occasional flake of gold in stock, and either set will ship forthwith.  
 
If you would like to choose a different color(s), you can contact us and we will make a set for you.  Made to order sets should ship in about a week.  
 
Each coasters measures 4" square, and they are 1/4 to 3/8" thick.  Each coaster has a cork bottom to protect your furniture and they are finished in a food safe wood butter (a blend of oil and wax).  Enjoy!
 
P.s. Unlike my table products, do to their size, this river is faux (meaning that it was created by me).