You can use a set of 400+ icons from Font Awesome
<i class="fa fa-heart"></i> fa-heart
Result:
�
fa-heart
? fa-adjust[]
? fa-adn[]
? fa-align-center[]
? fa-align-justify[]
? fa-align-left[]
? fa-align-right[]
? fa-ambulance[]
? fa-anchor[]
? fa-android[]
? fa-angle-double-down[]
? fa-angle-double-left[]
? fa-angle-double-right[]
? fa-angle-double-up[]
? fa-angle-down[]
? fa-angle-left[]
? fa-angle-right[]
? fa-angle-up[]
? fa-apple[]
? fa-archive[]
? fa-arrow-circle-down[]
? fa-arrow-circle-left[]
? fa-arrow-circle-o-down[]
? fa-arrow-circle-o-left[]
? fa-arrow-circle-o-right[]
? fa-arrow-circle-o-up[]
? fa-arrow-circle-right[]
? fa-arrow-circle-up[]
? fa-arrow-down[]
? fa-arrow-left[]
? fa-arrow-right[]
? fa-arrow-up[]
? fa-arrows[]
? fa-arrows-alt[]
? fa-arrows-h[]
? fa-arrows-v[]
? fa-asterisk[]
? fa-automobile(alias)[]
? fa-backward[]
? fa-ban[]
? fa-bank(alias)[]
? fa-bar-chart-o[]
? fa-barcode[]
? fa-bars[]
? fa-beer[]
? fa-behance[]
? fa-behance-square[]
? fa-bell[]
? fa-bell-o[]
? fa-bitbucket[]
? fa-bitbucket-square[]
? fa-bitcoin(alias)[]
? fa-bold[]
? fa-bolt[]
? fa-bomb[]
? fa-book[]
? fa-bookmark[]
? fa-bookmark-o[]
? fa-briefcase[]
? fa-btc[]
? fa-bug[]
? fa-building[]
? fa-building-o[]
? fa-bullhorn[]
? fa-bullseye[]
? fa-cab(alias)[]
? fa-calendar[]
? fa-calendar-o[]
? fa-camera[]
? fa-camera-retro[]
? fa-car[]
? fa-caret-down[]
? fa-caret-left[]
? fa-caret-right[]
? fa-caret-square-o-down[]
? fa-caret-square-o-left[]
? fa-caret-square-o-right[]
? fa-caret-square-o-up[]
? fa-caret-up[]
? fa-certificate[]
? fa-chain(alias)[]
? fa-chain-broken[]
? fa-check[]
? fa-check-circle[]
? fa-check-circle-o[]
? fa-check-square[]
? fa-check-square-o[]
? fa-chevron-circle-down[]
? fa-chevron-circle-left[]
? fa-chevron-circle-right[]
? fa-chevron-circle-up[]
? fa-chevron-down[]
? fa-chevron-left[]
? fa-chevron-right[]
? fa-chevron-up[]
? fa-child[]
? fa-circle[]
? fa-circle-o[]
? fa-circle-o-notch[]
? fa-circle-thin[]
? fa-clipboard[]
? fa-clock-o[]
? fa-cloud[]
? fa-cloud-download[]
? fa-cloud-upload[]
? fa-cny(alias)[]
? fa-code[]
? fa-code-fork[]
? fa-codepen[]
? fa-coffee[]
? fa-cog[]
? fa-cogs[]
? fa-columns[]
? fa-comment[]
? fa-comment-o[]
? fa-comments[]
? fa-comments-o[]
? fa-compass[]
? fa-compress[]
? fa-copy(alias)[]
? fa-credit-card[]
? fa-crop[]
? fa-crosshairs[]
? fa-css3[]
? fa-cube[]
? fa-cubes[]
? fa-cut(alias)[]
? fa-cutlery[]
? fa-dashboard(alias)[]
? fa-database[]
? fa-dedent(alias)[]
? fa-delicious[]
? fa-desktop[]
? fa-deviantart[]
? fa-digg[]
? fa-dollar(alias)[]
? fa-dot-circle-o[]
? fa-download[]
? fa-dribbble[]
? fa-dropbox[]
? fa-drupal[]
? fa-edit(alias)[]
? fa-eject[]
? fa-ellipsis-h[]
? fa-ellipsis-v[]
? fa-empire[]
? fa-envelope[]
? fa-envelope-o[]
? fa-envelope-square[]
? fa-eraser[]
? fa-eur[]
? fa-euro(alias)[]
? fa-exchange[]
? fa-exclamation[]
? fa-exclamation-circle[]
? fa-exclamation-triangle[]
? fa-expand[]
? fa-external-link[]
? fa-external-link-square[]
? fa-eye[]
? fa-eye-slash[]
? fa-facebook[]
? fa-facebook-square[]
? fa-fast-backward[]
? fa-fast-forward[]
? fa-fax[]
? fa-female[]
? fa-fighter-jet[]
? fa-file[]
? fa-file-archive-o[]
? fa-file-audio-o[]
? fa-file-code-o[]
? fa-file-excel-o[]
? fa-file-image-o[]
? fa-file-movie-o(alias)[]
? fa-file-o[]
? fa-file-pdf-o[]
? fa-file-photo-o(alias)[]
? fa-file-picture-o(alias)[]
? fa-file-powerpoint-o[]
? fa-file-sound-o(alias)[]
? fa-file-text[]
? fa-file-text-o[]
? fa-file-video-o[]
? fa-file-word-o[]
? fa-file-zip-o(alias)[]
? fa-files-o[]
? fa-film[]
? fa-filter[]
? fa-fire[]
? fa-fire-extinguisher[]
? fa-flag[]
? fa-flag-checkered[]
? fa-flag-o[]
? fa-flash(alias)[]
? fa-flask[]
? fa-flickr[]
? fa-floppy-o[]
? fa-folder[]
? fa-folder-o[]
? fa-folder-open[]
? fa-folder-open-o[]
? fa-font[]
? fa-forward[]
? fa-foursquare[]
? fa-frown-o[]
? fa-gamepad[]
? fa-gavel[]
? fa-gbp[]
? fa-ge(alias)[]
? fa-gear(alias)[]
? fa-gears(alias)[]
? fa-gift[]
? fa-git[]
? fa-git-square[]
? fa-github[]
? fa-github-alt[]
? fa-github-square[]
? fa-gittip[]
? fa-glass[]
? fa-globe[]
? fa-google[]
? fa-google-plus[]
? fa-google-plus-square[]
? fa-graduation-cap[]
? fa-group(alias)[]
? fa-h-square[]
? fa-hacker-news[]
? fa-hand-o-down[]
? fa-hand-o-left[]
? fa-hand-o-right[]
? fa-hand-o-up[]
? fa-hdd-o[]
? fa-header[]
? fa-headphones[]
? fa-heart[]
? fa-heart-o[]
? fa-history[]
? fa-home[]
? fa-hospital-o[]
? fa-html5[]
? fa-image(alias)[]
? fa-inbox[]
? fa-indent[]
? fa-info[]
? fa-info-circle[]
? fa-inr[]
? fa-instagram[]
? fa-institution(alias)[]
? fa-italic[]
? fa-joomla[]
? fa-jpy[]
? fa-jsfiddle[]
? fa-key[]
? fa-keyboard-o[]
? fa-krw[]
? fa-language[]
? fa-laptop[]
? fa-leaf[]
? fa-legal(alias)[]
? fa-lemon-o[]
? fa-level-down[]
? fa-level-up[]
? fa-life-bouy(alias)[]
? fa-life-ring[]
? fa-life-saver(alias)[]
? fa-lightbulb-o[]
? fa-link[]
? fa-linkedin[]
? fa-linkedin-square[]
? fa-linux[]
? fa-list[]
? fa-list-alt[]
? fa-list-ol[]
? fa-list-ul[]
? fa-location-arrow[]
? fa-lock[]
? fa-long-arrow-down[]
? fa-long-arrow-left[]
? fa-long-arrow-right[]
? fa-long-arrow-up[]
? fa-magic[]
? fa-magnet[]
? fa-mail-forward(alias)[]
? fa-mail-reply(alias)[]
? fa-mail-reply-all(alias)[]
? fa-male[]
? fa-map-marker[]
? fa-maxcdn[]
? fa-medkit[]
? fa-meh-o[]
? fa-microphone[]
? fa-microphone-slash[]
? fa-minus[]
? fa-minus-circle[]
? fa-minus-square[]
? fa-minus-square-o[]
? fa-mobile[]
? fa-mobile-phone(alias)[]
? fa-money[]
? fa-moon-o[]
? fa-mortar-board(alias)[]
? fa-music[]
? fa-navicon(alias)[]
? fa-openid[]
? fa-outdent[]
? fa-pagelines[]
? fa-paper-plane[]
? fa-paper-plane-o[]
? fa-paperclip[]
? fa-paragraph[]
? fa-paste(alias)[]
? fa-pause[]
? fa-paw[]
? fa-pencil[]
? fa-pencil-square[]
? fa-pencil-square-o[]
? fa-phone[]
? fa-phone-square[]
? fa-photo(alias)[]
? fa-picture-o[]
? fa-pied-piper[]
? fa-pied-piper-alt[]
? fa-pied-piper-square(alias)[]
? fa-pinterest[]
? fa-pinterest-square[]
? fa-plane[]
? fa-play[]
? fa-play-circle[]
? fa-play-circle-o[]
? fa-plus[]
? fa-plus-circle[]
? fa-plus-square[]
? fa-plus-square-o[]
? fa-power-off[]
? fa-print[]
? fa-puzzle-piece[]
? fa-qq[]
? fa-qrcode[]
? fa-question[]
? fa-question-circle[]
? fa-quote-left[]
? fa-quote-right[]
? fa-ra(alias)[]
? fa-random[]
? fa-rebel[]
? fa-recycle[]
? fa-reddit[]
? fa-reddit-square[]
? fa-refresh[]
? fa-renren[]
? fa-reorder(alias)[]
? fa-repeat[]
? fa-reply[]
? fa-reply-all[]
? fa-retweet[]
? fa-rmb(alias)[]
? fa-road[]
? fa-rocket[]
? fa-rotate-left(alias)[]
? fa-rotate-right(alias)[]
? fa-rouble(alias)[]
? fa-rss[]
? fa-rss-square[]
? fa-rub[]
? fa-ruble(alias)[]
? fa-rupee(alias)[]
? fa-save(alias)[]
? fa-scissors[]
? fa-search[]
? fa-search-minus[]
? fa-search-plus[]
? fa-send(alias)[]
? fa-send-o(alias)[]
? fa-share[]
? fa-share-alt[]
? fa-share-alt-square[]
? fa-share-square[]
? fa-share-square-o[]
? fa-shield[]
? fa-shopping-cart[]
? fa-sign-in[]
? fa-sign-out[]
? fa-signal[]
? fa-sitemap[]
? fa-skype[]
? fa-slack[]
? fa-sliders[]
? fa-smile-o[]
? fa-sort[]
? fa-sort-alpha-asc[]
? fa-sort-alpha-desc[]
? fa-sort-amount-asc[]
? fa-sort-amount-desc[]
? fa-sort-asc[]
? fa-sort-desc[]
? fa-sort-down(alias)[]
? fa-sort-numeric-asc[]
? fa-sort-numeric-desc[]
? fa-sort-up(alias)[]
? fa-soundcloud[]
? fa-space-shuttle[]
? fa-spinner[]
? fa-spoon[]
? fa-spotify[]
? fa-square[]
? fa-square-o[]
? fa-stack-exchange[]
? fa-stack-overflow[]
? fa-star[]
? fa-star-half[]
? fa-star-half-empty(alias)[]
? fa-star-half-full(alias)[]
? fa-star-half-o[]
? fa-star-o[]
? fa-steam[]
? fa-steam-square[]
? fa-step-backward[]
? fa-step-forward[]
? fa-stethoscope[]
? fa-stop[]
? fa-strikethrough[]
? fa-stumbleupon[]
? fa-stumbleupon-circle[]
? fa-subscript[]
? fa-suitcase[]
? fa-sun-o[]
? fa-superscript[]
? fa-support(alias)[]
? fa-table[]
? fa-tablet[]
? fa-tachometer[]
? fa-tag[]
? fa-tags[]
? fa-tasks[]
? fa-taxi[]
? fa-tencent-weibo[]
? fa-terminal[]
? fa-text-height[]
? fa-text-width[]
? fa-th[]
? fa-th-large[]
? fa-th-list[]
? fa-thumb-tack[]
? fa-thumbs-down[]
? fa-thumbs-o-down[]
? fa-thumbs-o-up[]
? fa-thumbs-up[]
? fa-ticket[]
? fa-times[]
? fa-times-circle[]
? fa-times-circle-o[]
? fa-tint[]
? fa-toggle-down(alias)[]
? fa-toggle-left(alias)[]
? fa-toggle-right(alias)[]
? fa-toggle-up(alias)[]
? fa-trash-o[]
? fa-tree[]
? fa-trello[]
? fa-trophy[]
? fa-truck[]
? fa-try[]
? fa-tumblr[]
? fa-tumblr-square[&#xf174;]
? fa-turkish-lira(alias)[]
? fa-twitter[]
? fa-twitter-square[]
? fa-umbrella[]
? fa-underline[]
? fa-undo[]
? fa-university[]
? fa-unlink(alias)[]
? fa-unlock[]
? fa-unlock-alt[]
? fa-unsorted(alias)[]
? fa-upload[]
? fa-usd[]
? fa-user[]
? fa-user-md[]
? fa-users[]
? fa-video-camera[]
? fa-vimeo-square[]
? fa-vine[]
? fa-vk[]
? fa-volume-down[]
? fa-volume-off[]
? fa-volume-up[]
? fa-warning(alias)[]
? fa-wechat(alias)[]
? fa-weibo[]
? fa-weixin[]
? fa-wheelchair[]
? fa-windows[]
? fa-won(alias)[]
? fa-wordpress[]
? fa-wrench[]
? fa-xing[]
? fa-xing-square[]
? fa-yahoo[]
? fa-yen(alias)[]
? fa-youtube[]
? fa-youtube-play[]
? fa-youtube-square[]