Cinnabar is a semi-precious stone found in several places around the world, but this intricately-carved stone has its origins in China.  The 1-1/8" by 5/8" ring has a floral motif and is deeply set in the sterling.  Ring size is probably a 4 to 6 but could be sized without difficulty.  This is a stunner that will bring attention to your beautiful hands.  As with the other pieces of this set, the price shown is half original price.