Large crystals of <a href="https://en.wikipedia.org/wiki/Kyanite" class="extiw" title="en:Kyanite">Kyanite</a>.
<a href="//commons.wikimedia.org/wiki/User:The_High_Fin_Sperm_Whale" title="User:The High Fin Sperm Whale">The High Fin Sperm Whale</a>
CC BY-SA 3.0
<span class="int-own-work">Self-photographed</span>