Hyperlink icon (How to change the image)

Hello,

Everyone knows about that icon, a vector illustration of a chain that usually sits to the right of a hyperlink (when it is linked on a WordPress widget, or within a post?) I need to know if that icon could be changed into some other image like a bullet per say?

I would at least like to find out if anyone knows if that icon can be removed, or ignored from a command within the style-sheet or somewhere else in the editor?

Thanks.