<a href="https://en.wikipedia.org/wiki/Magnetite" class="extiw" title="en:Magnetite">Magnetite</a> (Fe<sub>3</sub>O<sub>4</sub>), location: Serafimovka, Primorsky Krai, Russia.
<a href="//commons.wikimedia.org/wiki/User:Norbert_Kaiser" title="User:Norbert Kaiser">Norbert Kaiser</a>
CC BY-SA 2.5
<span class="int-own-work">Self-photographed</span>