Where are the default system symbols for folders and also documents saved?
The default symbols are saved in numerous areas inside
/System/Library - exists a details icon you're seeking?
/System/Library/CoreServices/Finder.app/Contents/Resources) has the Smart Folder symbols and also the Burnable folder symbols as an example.
A lot of the extra well-known symbols (eg. images for the default folders amongst several others) can be located at