Side view of typical “Button Rock” concretions found within Schoharie County, New York. <a href="https://en.wiktionary.org/wiki/scale_cube" class="extiw" title="wikt:scale cube">Scale cube</a> at top center of image is 1 cm on each edge (marked with white "W").
Paul Heinrich
CC BY 3.0
<span class="int-own-work" lang="en">Own work</span>