Verbal descriptions of object shape are frequently accompanied by iconic gestures expressing meaning via similarity to the referent. This paper presents a study examining the morphological variety of shape-related iconic gestures and the way they express aspects of object shape. It is shown that information about object extent, object boundary, and part structure is reflected both in coverbal gestures and their verbal affiliates. Based on the empirical results, a computational model for the representation and processing of multimodally communicated object shape is proposed.