According to Sear Aes Rude
served the economic needs of central Italy
prior to the introduction of coined money
. They took the form of irregular lumps of bronze of widely varying weight and lacking any kind of official stamp or mark of value. The range of weight seems to be from c.8gms to over 300gms.
Without a secure archaeological context I do not see how one could differentiate between genuine Aes Rude
and irregular lumps of bronze of indeterminate date and origin which could simply be a bronze-smith's scrap.