Alum, KAl(SO<sub>4</sub>)<sub>2</sub>•12 H<sub>2</sub>O; Staatliches Museum für Naturkunde Karlsruhe, Germany. Used in homeopathy as remedy: Alumen (Alumn.)
<a href="//commons.wikimedia.org/wiki/User:Llez" title="User:Llez">H. Zell</a>
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<span class="int-own-work" lang="en">Own work</span>