It measures roughly 30 centimetres high and 17 centimetres wide, with barely a centimetre of its thickness visible above the surrounding masonry. What makes it remarkable is what is carved onto that exposed face: a precise, equal-armed cross, the kind known as a cross-in-square or outline cross, with rectangular expansions at each of its four terminals and a square expansion where the arms meet. Above the cross, running in a horizontal line, is a fragmentary inscription, its final letter pressing right up against the top of the upper arm, as though the carver ran out of room, or perhaps intended the text and the cross to touch.

The stone came to light during an excavation in 1944, recorded by Duignan and subsequently noted by the epigrapher R.A.S. Macalister in 1949. It is catalogued as Toureen Peacaun 25, suggesting it belongs to a broader group of early medieval inscribed stones associated with the site. Scholars Okasha and Forsyth, writing in 2001, described it as a fragment of a slab whose original form is no longer known, meaning what survives is only a portion of something once larger. The inscription itself is incomplete, its full text unrecoverable from what remains. Early medieval cross-slabs of this type, carved with incised outline crosses and occasional inscriptions, were typically memorial stones, marking the graves of individuals and sometimes recording their names or a prayer on their behalf. Whether this one did so in full, before it was broken and eventually pressed into the church wall, cannot now be determined.