Items that can be converted into gems

[iFedix]

Hey guys! I want to update Dustman addon in order to mark as junk/delete crown related stuff obtained by daily rewards. Problem is that those exact same items can be found also when opening crates and gems can be extracted using them (so I don't want to delete those).
So, is there any method (like canGemsBeExtracted(itemLink)) or id in itemLink that I can use to distinguish the different versions of items?
Here an example of what I am talking about:

Thank you!