The piece measures just 0.64 metres long and 0.42 metres wide, cut from fossiliferous limestone, the kind of stone packed with the compressed remains of ancient marine organisms that gives much of Kilkenny's medieval stonework its distinctive texture. What remains of the inscription, carved in raised relief Latin blackletter, reads: BURGES' VILLOE KILKENIE Q, a partial phrase that translates roughly as "burgess of the town of Kilkenny who died..." and then stops. The name, the date of death, and much of the formula that once followed have gone with the missing portions of the slab.

The fragment dates to the sixteenth century and is thought to have originally formed part of a chest tomb or ledger, possibly serving as a mensa, the flat stone top of an altar-like tomb structure. The person it commemorated was a burgess, meaning a full citizen of the medieval town with specific legal and commercial rights, a status of some consequence in a place as commercially active as late medieval Kilkenny. The fragment was recorded by Bradley in 1980 and is now built into the wall of the Bryan Vault, a secondary resting place of sorts for a piece of stonework that was almost certainly displaced, broken, or repurposed at some point after the Reformation, when the fates of many such monuments became uncertain. The vault itself is a named family burial space within the church, which speaks to the layered and long-occupied character of St Mary's as a site of civic and religious memory.