Set into the west face of a cross wall at St Mary's parish church, it is not a graveslab in the way most people would picture one, flat and legible underfoot. It is a rectangular fragment, roughly half a metre by a third, broken from the top of what was once a complete slab, and it has been doing structural work here since 1804, mortared into a wall that connects the south side of the church with the surrounding churchyard boundary.

The slab itself dates from the 13th or 14th century and is carved from fossiliferous limestone, a stone formed from the compressed remains of ancient marine organisms, whose texture gives medieval Kilkenny stonework much of its distinctive character. The decoration is executed in false-relief, a technique in which the background is cut away to leave the design standing proud of the surface, and it shows a three-armed cross with fleur-de-lis terminals, the cross-shaft truncated below the head where the stone was broken. There is no inscription, which was not unusual for the period; many medieval grave markers relied entirely on their carved ornament to signal status and devotion. The slab was first documented by John Bradley in 1980, who catalogued it as part of a wider study of Kilkenny's medieval funerary monuments. What is quietly striking is the object's biography: carved to mark a particular death in the medieval city, it was later broken, its original purpose abandoned, and finally pressed into service as building material when somebody needed to put up a wall in the early nineteenth century.