<Viewbox
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:fa="http://schemas.fontawesome.io/icons/"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Grid>
        <fa:ImageAwesome Foreground="Gray" Icon="InfoCircle" Margin="10" />
    </Grid>
</Viewbox>