It is classified as a cross or cross shaft, but nothing about its modest dimensions announces that designation. What marks it out is a single vertical groove running up the centre of each face, the two grooves meeting across the top of the pillar to form an implied cross, carved rather than cut through the stone. The technique is restrained to the point of abstraction.

The pillar is made of mica-schist, a local metamorphic rock with a characteristically layered, slightly lustrous surface. Patrick Healy, who recorded it in an unpublished Office of Public Works survey of ancient monuments at Glendalough in 1972, noted that the stone shows evidence of very fine pocking across its surface, a pecking technique used to shape or decorate early medieval stonework, though the worked surface has since partially flaked away. The pillar measures 0.45 metres high, 0.24 metres wide, and 0.11 metres thick. Those dimensions place it firmly in the tradition of early Irish cross-marked stones, simple upright markers that preceded the elaborately carved high crosses and which were often positioned in deliberate relationship to ecclesiastical structures. Its placement just west of the church gable is unlikely to be accidental; west-facing alignments carry their own weight in early Christian site planning.