Crystalized spell item is (from the inventory point of view) just another item sheet. From what Jahuu's mockup icon tells me, you wish the crystalized spell item to have icon by the matter of a crystalized spell inside.
I think it would need to add new sheets (and translations and icons) for all types you wish to have. Plus some coding around creating and using such items. And you also need to decide what to do with milion current crystalized spell items on all characters.
Other option is to do a hack over current system to adjust item visual look for the user. I am not sure if it is a good way generally, however I wonder how could this work with the API data exports, for example.
I think it would need to add new sheets (and translations and icons) for all types you wish to have. Plus some coding around creating and using such items. And you also need to decide what to do with milion current crystalized spell items on all characters.
Other option is to do a hack over current system to adjust item visual look for the user. I am not sure if it is a good way generally, however I wonder how could this work with the API data exports, for example.