It was a cupmarked stone, meaning it bore one or more shallow, circular depressions ground into its surface by human hands in prehistory. Cup marks of this kind appear across Ireland, Britain, and much of Europe, and they remain genuinely puzzling: no consensus exists on whether they served a ritual, territorial, or purely symbolic purpose. What is certain is that someone, at some point in the prehistoric past, chose this particular stone on this particular slope and worked it deliberately.

Clear Island, or Oileán Chléire, sits off the south-west tip of Cork, and the north-east side of the island, where the stone originally lay, is among the more exposed and least trafficked parts of an already remote place. At some point after the stone was recorded in that location, it was moved for safekeeping to the Heritage Centre in Lios Ó Móine, where it is now on display. The site in the rough pasture therefore survives only as a location, the stone itself having been relocated rather than left to weather further or risk damage.