A SCSS mixin to use emojis as solid/stroked icons. See example at http://jsfiddle.net/andreasvirkus/yLebhoc7/11/

emoji-icons.scss

@mixin emoji-icon($color: var(--black), $size: 1rem) {
  font-size: $size;
  color: transparent;
  text-shadow: 0 0 $color;
}

@mixin emoji-icon-stroke($color: var(--black), $fill: var(--white)) {
  text-shadow: 0 0 $fill,
   -1px -1px 0 $color,
    1px -1px 0 $color,
    -1px 1px 0 $color,
     1px 1px 0 $color;
}