node_modules/material-icons/css/_mixins.scss

@import '../iconfont/mixins';

@function material-icons-content($codepoint) {
  @return unquote('"\\#{$codepoint}"');
}

@mixin material-icon($name, $pseudo: 'before') {
  $codepoint: map-get($material-icons-codepoints, $name);

  &::#{$pseudo} {
    content: material-icons-content($codepoint);
  }
}