<Icon name="user" />
Changing the prefix to use fontawesome
First you need to add font awesome to your project.
In your HTML :
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css">
Then use the Icon prefix prop
<Icon prefix="fa" name="user" />
Rendering a flag
<Icon flag name="gb" />
Rendering a payment icon
<Icon payment name="visa" />