The marking is easy to miss: eroded, covered in lichen, and cut into the stone's south-western face in a way that only particular light conditions are likely to reveal. Yet the cross, measuring roughly 40 centimetres high and 31 centimetres wide, carries traces of rounded terminals at the ends of its arms, a detail that links it to a recognisable early medieval tradition of cross-carving found throughout Ireland and the western Atlantic fringe.

The stone itself stands about 85 centimetres tall and is oriented along a north-west to south-east axis, aligned with the old field boundary on which it rests. Whether the stone originally served as a boundary marker that was later inscribed with a cross, or whether it was placed deliberately as a devotional object within a working agricultural landscape, is not recorded. Clear Island, known in Irish as Oileán Chléire, has a long history of early Christian activity, and cross-inscribed stones of this kind were often used to mark sacred ground, pilgrimage routes, or simply to Christianise older landscape features. The rounded terminals on the arms of the cross are a common characteristic of early medieval examples, though the erosion here makes a precise dating difficult.