It is not. The slab, irregular in shape and modest in scale, carries a carved outline cross whose shaft ends in widely splayed, open terminals, a style associated with early medieval Christian carving in Ireland. These splayed terminals, sometimes called expanded or forked ends, are a feature that appears across early ecclesiastical sites and helps date or at least place a stone within a broad tradition of insular Christian craft.

The slab measures roughly 0.7 metres at its longest, 0.32 metres across at its widest, and averages about 0.06 metres in thickness. It is sandstone, a material that weathers and flakes over time, which makes the survival of any legible carving on it quietly remarkable. Church Island itself belongs to the constellation of early monastic sites scattered across the lakes and inlets of the Iveragh Peninsula in south Kerry, a landscape that contains an unusual density of early Christian remains. The cross-slab is recorded in Aidan O'Sullivan and John Sheehan's archaeological survey of the Iveragh Peninsula, published by Cork University Press in 1996, which remains the standard reference for the area's pre-Norman heritage.