Brockage Rarity Examined

443, Lot: 469. Estimate $100. Sold for $575. This amount does not include the buyer’s fee.

M. Plaetorius M.f. Cestianus. 57 BC. AR Brockage Denarius (16.5mm, 3.89 g, 12h). Rome mint. Draped female bust left, wearing winged diadem; staff behind / Incuse of obverse. Cf. Crawford 405/1b; cf. Sydenham 799; cf. Plaetoria 9; cf. RBW 1447; all for obverse type. VF, lightly toned. Very rare.

From the Andrew McCabe Collection. Ex Numismatik Naumann 58 (1 October 2017), lot 409.

The reverse die of this coin type, if one could see its impression, would have had an Anguipede Giant in a temple pediment. The obverses come with symbols, this carrying a staff symbol behind the head. Brockages occur in approximate proportion to issue size. That’s an attribute that makes brockages useful for rule of thumb judgements about the size of an issue. It is a lot easier to count a handful of brockages than hundreds of ordinary denarii, especially as brockages have the additional merit of being collected no matter how common the underlying coin type is. “Brockage denarius” provides 571 results on acsearch, mostly Roman Republican coins. A quick look through those results shows a preponderance of common types, but also allows you to determine which coin types, even though expensive, are, in fact, common. There are a dozen Julius Caesar brockages in available records – half of which are Caesar portrait types – and also several elephants and Aeneas Anchises types. Julius Caesar coins appear multiple times in the brockage record, because they are very common types – many thousand Caesar portrait types must be in the market for there to be half dozen brockages sold in the last decade. In fact, the search results ratio between “denarius” and “brockage denarius” is approximately 500:1. This Anguipede Giant type has had about a dozen examples sold over the last twenty years. It’s the sort of rarity whose numbers are so low that one never sees a brockage of it. I bought this coin because of this rarity factor and the illustrative story behind it. It would have been even nicer had it been a reverse brockage of that giant in the temple! [Andrew McCabe]