Do you have it in the html view of the snippet? Or in the WYSIWYG editor?

What you pass to Snippets inside the {snippet} tag is not raw text. It is passed as html/rich text. So if you want an   there, you need to place it in the html view.
So in the article (or whatever content it is) where you have that {snippet} tag, switch to the HTML view in the editor, and add the   there.
So there it would look something like: