Migmatite, Veporské vrchy Mts. (Western Carpathians, Slovakia), Veporic Unit, Devonian. Photo taken at the National Museum in Bratislava.
<a href="//commons.wikimedia.org/wiki/User:Pelex" title="User:Pelex">Pelex</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>