This size 6 Sterling Silver ring features a 20 X 17 quartz drusy.  The drusy has several interesting aspects, first-the naturally clear drusy crystals have a vapor deposition layer of copper and secondly-the  stone gives the apperance of two images, depending on which way you view them.  One view(if you squint a little) is of a horse and rider while the other image portrays a running man.  On a more symbolic and mushy note, when you look at the ring from the ends it has an O while the sides have X's.  I have carved (and discarded) more waxes for this stone than any other one the gift has ever owned.  Your pal in art, Al