mkdocs-material/material/.icons/fontawesome/solid/stop.svg

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 384 512"><!--! Font Awesome Free 6.4.2 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2023 Fonticons, Inc.--><path d="M0 128c0-35.3 28.7-64 64-64h256c35.3 0 64 28.7 64 64v256c0 35.3-28.7 64-64 64H64c-35.3 0-64-28.7-64-64V128z"/></svg>