Organization of 500+ items

Our team has to work with a very large number of image resources (over 500). We're struggling to figure out how best to organize these items such that they are easy to work with. We're specifically dealing with icons. How should we organize them into groups so designers can easily find what they are looking for?

One issue we're facing is that one icon could be used in different situations and has different meanings. For example, a "star" icon could be an action to add something to "Favorites". Also, the section "Favorites" has "star" icon as well. This icon fits equally well in multiple categories, so should we place it in the "Actions" category, "Containers", or both?

How should we organize such a large number of resources?