twitter-bootstrap-glyphicon

As of today glyphicons come in a separate css.

To use do the following.

application.html.erb

<head>
  <link href="//netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap-glyphicons.css" rel="stylesheet">
</head>

Then drop in a page using:

<button type="button" class="btn btn-default btn-lg">
  <span class="glyphicon glyphicon-star"></span> Star
</button>

Links that help:
http://getbootstrap.com/components/#glyphicons
http://stackoverflow.com/questions/18205738/how-to-use-glyphicons-in-bootstrap-3-0