Using icon to denote double asset.

src/components/farm/Board.jsx

@@ -31,7 +31,7 @@ import { connect } from 'react-redux'
 import { FontAwesomeIcon } from '@fortawesome/react-fontawesome'
 import { faUser, faUsers, faTractor, faWindowRestore,
          faDollarSign, faTimes, faAsterisk, faExchangeAlt,
-         faInfoCircle, faArrowUp } from '@fortawesome/free-solid-svg-icons'
+         faInfoCircle, faArrowUp, faAward } from '@fortawesome/free-solid-svg-icons'
 
 import { GroupBox, Row, Col, Button } from '../widgets.jsx'
 import SpaceNode from './SpaceNode.jsx'
@@ -181,7 +181,9 @@ class ResourceUnit extends React.Component {
                 {this.props.img ? (<img src={this.props.img} />) : (<Fragment />)}
                 {this.props.children}
                 {this.props.doubled ? (
-                     <p>x2!</p>
+                     <div className="resource-doubled">
+                         <FontAwesomeIcon icon={faAward} />
+                     </div>
                 ) : (<></>)}
             </div>
         );