Hematite nanoparticles (20 nm) self-organized into a micro-heart or nothing is random
<a href="//commons.wikimedia.org/w/index.php?title=User:Iacob.mihail&amp;action=edit&amp;redlink=1" class="new" title="User:Iacob.mihail (page does not exist)">Iacob Mihail</a>
<span class="int-own-work" lang="en">Own work</span>