Originally laid flat as recumbent grave markers, the majority have been stood upright over the centuries and pressed into service as conventional headstones, a practical reuse that has left their carved surfaces partially buried in the earth. Most are cut from local schist, though four are granite, and because so much of each slab is now below ground, the carvings that remain visible are only a fraction of what was once there.

One slab in particular has a more complicated history. Writing in 1925, Crawford described a small wedge-shaped piece of slate, roughly 0.9 metres long and tapering to a point, found near the south-east angle of the ruined church at Aghowle. Its shape, he noted, made it quite unsuited to standing in a socket, suggesting it was never a free-standing cross in the conventional sense. On one face is carved a Greek cross, the arms flaring slightly at their ends and enclosed within a circle just over 22 centimetres in diameter. On the reverse is something more arresting: a human head or mask, roughly the same scale as the cross opposite. Crawford also noted that an earlier scholar, Graves, writing in 1883, had mentioned a small cross-base near the east end of the church and a cross that appeared to have stood on it, repurposed as a grave headstone nearby. Whether Graves was referring to this same object is unclear. What is clear is that the slab Crawford described can no longer be located with certainty within the graveyard, though photographs taken at some point show it set into one of the holed cross-bases on site, a socket stone designed to receive and hold an upright cross, with a rectangular stone trough visible in the background.