This symbol is the ancient Egyptian <i>ankh</i>. It is also known as "the key of life." It symbolizes life, including the continuation of life in the underworld.
<a href="//commons.wikimedia.org/w/index.php?title=User:Alexihelligar&amp;action=edit&amp;redlink=1" class="new" title="User:Alexihelligar (page does not exist)">Alexi Helligar</a>
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<span class="int-own-work" lang="en">Own work</span>