Can add a icon as SVG-HTML, a dashicon string or with a custom icon classname. Other than that it’s the same as the Dashicon component.
<Icon
icon={
<svg>
<path d="M5 4v3h5.5v12h3V7H19V4z" />
</svg>
}
/>
<p>Another icon:</p>
<Icon
icon="smiley"
size={56}
/>