the piece has an interesting fractal surface caused by the nature of the high voltage that passed through the sand that was struck
<a href="//commons.wikimedia.org/w/index.php?title=User:Beeblaine&amp;action=edit&amp;redlink=1" class="new" title="User:Beeblaine (page does not exist)">Beeblaine</a>
CC BY 4.0
<span class="int-own-work" lang="en">Own work</span>