It bore two markings: a shallow cup, roughly four and a half centimetres wide and two and a half centimetres deep, scooped into its surface, and beside that, an equal-armed incised cross just over seven centimetres across. A chancel arch, for those unfamiliar with early church architecture, is the structural opening that separates the nave of a church from the chancel, or altar end, and objects placed in or near it often carried devotional significance. This particular stone, ovoid in shape and no more than eighteen centimetres long, was not set into a wall or displayed on a plinth. It was simply lying there, as if it had been set down and forgotten.

The sole detailed record of the stone comes from O'Reilly, writing in 1901, who measured and described it with some care and included a photograph on page 141 of his article. His account gives us the dimensions with precision: fifteen inches long, between five and seven inches thick, with the cup measuring one and three-quarter inches wide and one inch deep. Cup marks, which are circular depressions ground or pecked into stone, appear across early medieval and prehistoric Irish contexts, sometimes in association with cross motifs, though their exact function remains a matter of ongoing debate among archaeologists. The equal-armed cross beside it, incised rather than raised, is a form found frequently on early Christian stones throughout Ireland. Beyond O'Reilly's 1901 description, no further documentation of the stone's history or origins appears to have survived.

The present location of the stone is unknown. It is not clear whether it was removed, lost during building work, or simply misplaced at some point in the intervening century. Tully Church, the site where O'Reilly found it, lies in the Laughanstown area of south Dublin, and its ruins are accessible, but a visitor looking for this particular fragment will find no trace of it there now. What survives is O'Reilly's photograph and his careful measurements, a record precise enough to identify the stone if it were ever to resurface in a collection, a garden wall, or a storeroom somewhere.