leaflet fa markers

 var blueMarker = L . marker ( [ lat , lon ] , {
  icon : L . icon . fontAwesome ( {
    iconClasses : "fa fa-info-circle" , // you _could_ add other icon classes, not tested.
    // marker/background style
    markerColor : "#00a9ce" ,
    markerFillOpacity : 0.2 ,
    markerStrokeWidth : 1 ,
    markerStrokeColor : "grey" ,
    // icon style
    iconColor : "#FFF"
  } )
} ) . addTo ( map ) ;

var spinningMarker = L . marker ( [ lat , lon ] , {
  icon : L . icon . fontAwesome ( {
    iconClasses : "fa fa-circle-o-notch fa-spin" ,
    markerColor : "#ff89b5" ,
    iconColor : "#FFF" ,
    // use XY offsets to nudge positioning of icons, negative accepted
    iconXOffset : - 2 ,
    iconYOffset : 0
  } )
} ) . addTo ( map ) ;

// update existing
blueMarker . options . icon . setStyle ( { markerColor : "#F00" } ) ;