Lucy--

From the description, it sounds as if you have a piece of what was
probably a British-made lustre decorated vessel (not the 18th
century variety but the 19th into 20th century revival lustre stuff).
The vessels, often pitchers, would have copper lustre and other
decorations, especially bands of other colors.  At the moment, I
can't give you a reference to look at or cite, but I will try to find an
illustration somewhere.  You can often find these pieces in antique
shops.

Meta Janowitz