<p>
    Test for <i><a href="rdar://problem/9528843">rdar://problem/9528843</a>
    STIX glyphs not rendered on this stackoverflow answer</i>.
</p>
<p>
    A black circle: <span style="font-size: xx-large;">&#x26ab;</span>
</p>
<p>
    Another black circle: <span style="font-size: xx-large; font-weight: bold;">&#x26ab;</span>
</p>