Breccia, <a href="https://en.wikipedia.org/wiki/Apollo_16" class="extiw" title="en:Apollo 16">Apollo 16</a> lunar sample 61195, collected at <a href="https://en.wikipedia.org/wiki/Flag_(crater)" class="extiw" title="en:Flag (crater)">Flag</a>, or Station 1 of the mission, on the Moon.  Small cube is 1 cm on a side. Original description: "coherent, medium grey breccia with a glassy matrix and abundant clasts; zap pits are surrounded with wide spall zones".
James Stuby based on NASA image<br>
<p>Cropped from original, which is in the public domain because it is a work of the U.S. Government (<a href="https://en.wikipedia.org/wiki/NASA" class="extiw" title="en:NASA">NASA</a>).<br></p>
<b>Immediate source</b>: Lunar and Planetary Institute, Lunar Sample Atlas<br>Sample 61195 <a rel="nofollow" class="external text" href="http://www.lpi.usra.edu/lunar/samples/atlas/images/hires/61195/S72-37972.jpg">Photo S72-37972</a> (<a rel="nofollow" class="external text" href="http://www.lpi.usra.edu/lunar/samples/atlas/detail/?mission=Apollo%2016&amp;sample=61195">description</a>)