Why wouldn't it just be a 12 sided die for gambling?
Plus, grapefruit-sized feels like way too big for this purpose.
It's the original 'Swiss Army' multi-tool created by Gallic blacksmiths (ordered by Negotiatores/Roman arms merchants in conjunction w/ Roman Auxiliary troop arms officers) for measurement/procurement/maintenance of Auxiliary troop, polearm weapon shafts.
https://www.quora.com/What-was-the-use-of-the-Roman-dodecahe...
However, I think we might we would see some wear if they they were die. Might see some blobs dented or knocked off if they were regularly being rolled in taverns and such.