Sterling Silver, 22K gold. Quiet, soft colors run through this Australian boulder opal, neutrals that go with anything.  (PLEASE SEE THE VIDEO THAT GIVES A SENSE OF THE SCALE)  It measures 1-1/2" long (down the finger) and is a size 8 to 8-1/2 ( I AM SORRY, IT IS NOT SIZEABLE)  EXCHANGES ACCEPTED 10 DAYS FROM RECEIPT