A fragment of an Oligocene shell conglomerate from the Glen Massey formation. Calcite has crystallised out from some of the shells
<a href="//commons.wikimedia.org/wiki/User:Haydenrjones" title="User:Haydenrjones">Haydenrjones</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>