This is really awesome. I love how they use a familiar item as a point of reference for sizing. “A quarter inch in diameter” is incredibly specific but still a bit vaporous in the human mind, but “that much of a penny” communicates actual size with remarkable clarity.
As an aside, Kate tells me that one of her Geology professors has a giant fake quarter, a few inches across, that he can use to fake photos like this. With that in mind, never trust anyone or anything!
