  In the Visual Heritage domain, search engines are expected to support
archaeologists and curators to address cross-correlation and searching across
multiple collections. Archaeological excavations return artifacts that often
are damaged with parts that are fragmented in more pieces or totally missing.
The notion of similarity among fragments cannot simply base on the geometric
shape but style, material, color, decorations, etc. are all important factors
that concur to this concept. In this work, we discuss to which extent the
existing techniques for 3D similarity matching are able to approach fragment
similarity, what is missing and what is necessary to be further developed.
