fa-quran icon in font awesome icons has 1 variant fas i.e.,solid.
fa-radiation-alt icon in font awesome icons has 1 variant fas i.e.,solid.
fa-random icon in font awesome icons has 1 variant fas i.e.,solid.
fa-reddit-square icon in font awesome icons is part of brand (fab) icons
fa-redo icon in font awesome icons has 1 variant fas i.e.,solid.
fa-redo-alt icon in font awesome icons has 1 variant fas i.e.,solid.
fa-remove-format icon in font awesome icons has 1 variant fas i.e.,solid.
fa-rss-square icon in font awesome icons has 1 variant fas i.e.,solid.
fa-running icon in font awesome icons has 1 variant fas i.e.,solid.
fa-sad-cry icon in font awesome icons has 2 variants regular (far) and solid (fas)