I'm currently making a read-only explorer GUI for my game and I want to use these icons like model, part, folder and more. I've tried looking around but I can't seem to find how to do it. Anyone know how?
After some research, I don't think there's a way to access the icon of the class. The only thing I found remotely close to what you're looking for is Instance.ClassName, but that doesn't give us the icon, only what class it is.
If there was a way to do this, it would be found here: https://developer.roblox.com/en-us/api-reference/class/Instance
Given that there is no obvious way to find the icons, you'll be better off uploading them as decals and applying that to an ImageLabel.