A searchable guide to the complete WordPress Icon Library (@wordpress/icons) package from Gutenberg.
import { Icon, plusCircle } from '@wordpress/icons';
<Icon icon={plusCircle} />
<svg xmlns="http://www.w3.org/2000/svg" viewBox="-2 -2 24 24" aria-hidden="true" focusable="false"><path d="M10 1c-5 0-9 4-9 9s4 9 9 9 9-4 9-9-4-9-9-9zm0 16c-3.9 0-7-3.1-7-7s3.1-7 7-7 7 3.1 7 7-3.1 7-7 7zm1-11H9v3H6v2h3v3h2v-3h3V9h-3V6zM10 1c-5 0-9 4-9 9s4 9 9 9 9-4 9-9-4-9-9-9zm0 16c-3.9 0-7-3.1-7-7s3.1-7 7-7 7 3.1 7 7-3.1 7-7 7zm1-11H9v3H6v2h3v3h2v-3h3V9h-3V6z"></path></svg>
plusCircle – WordPress Icon Library