Wedgewood jewelry

hello to all, hoping you can help. have a wedgewood cameo pin and or
necklace. white on blue encased in a gold bezel.the word rainbow is
stamped on the inside of the bezel.the wedgewood itself is stamped
wedgewood made in england S68. the white picture on the front is of
what looks like a mythological horse with wings and three figures of
people standing on what looks like a cloud.

thanks very much for any you can share. karen rand