Vesicular basalt, <a href="https://en.wikipedia.org/wiki/Apollo_15" class="extiw" title="en:Apollo 15">Apollo 15</a> lunar sample 15016, collected at Station 3 of the mission, on the moon.  Edge of cube at right is 1 inch.  This rock is sometimes referred to as the <a href="https://en.wikipedia.org/wiki/Seatbelt_basalt" class="extiw" title="en:Seatbelt basalt">seatbelt basalt</a>.
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 62295 <a rel="nofollow" class="external text" href="http://www.lpi.usra.edu/lunar/samples/atlas/images/hires/15016/S71-45477.jpg">Photo S71-45477</a> (<a rel="nofollow" class="external text" href="https://www.lpi.usra.edu/lunar/samples/#apollo15s">catalogue</a>)