A searchable guide to the complete WordPress Icon Library (@wordpress/icons) package from Gutenberg.
import { Icon, box } from '@wordpress/icons';
<Icon icon={box} />
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" aria-hidden="true" focusable="false"><path fill-rule="evenodd" d="M5 5.5h14a.5.5 0 01.5.5v1.5a.5.5 0 01-.5.5H5a.5.5 0 01-.5-.5V6a.5.5 0 01.5-.5zM4 9.232A2 2 0 013 7.5V6a2 2 0 012-2h14a2 2 0 012 2v1.5a2 2 0 01-1 1.732V18a2 2 0 01-2 2H6a2 2 0 01-2-2V9.232zm1.5.268V18a.5.5 0 00.5.5h12a.5.5 0 00.5-.5V9.5h-13z" clip-rule="evenodd"></path></svg>
box – WordPress Icon Library