The stone is not inscribed. It carries no chi-rho, no knotwork, no carved figure. What it has instead is a shape: a splayed rounded top that narrows to a waist and then splays outward again toward a base buried within the altar beneath it. The result is a figure-of-eight silhouette that reads, loosely, as a cross, though the stone itself offers no confirmation of that reading.

Neither the provenance nor the date of the slab is known. What is known is that the altar it stands in was built in the 1960s, and that the site has a longer history beneath it. A 1942 account by O'Kelly described what was then present as an altar of the penal days, a rough heap of stones marking a spot where Mass would have been celebrated in secret during the eighteenth century, when Catholic worship was suppressed under the Penal Laws and open-air Mass rocks served as makeshift places of congregation. That earlier account makes no mention of this stone slab at all, which raises a quiet puzzle: the stone may have been placed here only when the current altar was constructed, or it may have been present but simply unremarked upon. There is no way to resolve this from the available evidence, and the stone keeps its own counsel on the matter.