It stands just 1.2 metres tall, measuring roughly 74 centimetres by 46 centimetres across its face, with its long axis oriented northeast to southwest. That alignment, modest as it sounds, is the kind of detail that quietly nags at archaeologists, since many Irish standing stones appear to have been positioned with deliberate regard to solar or lunar orientations, though whether this particular stone was set with any such intention remains unknown.

Standing stones of this kind are among the most enigmatic survivals in the Irish landscape. Erected during the Bronze Age in most documented cases, though some may be earlier or later, they were set upright as single unworked or lightly shaped blocks, and their original purposes are still debated. Some may have marked boundaries, burial sites, routeways, or meeting points; others may have carried ritual significance now entirely lost. The stone at Ballynagrumoolia is a rectangular example, which distinguishes it slightly from the more irregular boulders sometimes pressed into service, suggesting at least a degree of selection in the choice of material. Beyond its recorded dimensions and its position on a gently sloping field in County Cork, the historical record is sparse.