mkdocs-material/material/templates/.icons/simple/keystone.svg

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4.5 0A4.5 4.5 0 0 0 0 4.5v15A4.5 4.5 0 0 0 4.5 24h15a4.5 4.5 0 0 0 4.5-4.5v-15A4.5 4.5 0 0 0 19.5 0zm5.47 14.789v3.586H6.744V5.692H9.97v5.45h.167l4.218-5.45h3.463l-4.385 5.599 4.64 7.084h-3.788l-3.2-5.001z"/></svg>