Hi Cathy -
To my eye they appear different in the color and quality of brilliance, but it also depends on the quality of the diamond you're using for comparison - stone, cut and setting. For cut, I have seen similar cut names used for both in jewelry. eg: brilliant, radiant, etc.. These terms are uses quite loosely in the retail world, of course, so you have to understand what you're looking at just as is the case with pearls.