Roman Republic AR Denarius(3.17g, 20mm), "GR" series(Sempronius Gracchus?), 199-170 B.C., Uncertain mint. Helmeted head of Roma right; behind, X / The Dioscuri galloping right; below, GR; in exergue, ROMA. Crawford 169/1
Ex Peus, via MA-Shops, 7 Jan 2020, ex Peus e-Auction 6, 13 Jan 2018, lot 129, ex Lucernae, listed on VCoins 17 October 2017, ex Ibercoin Tarkis 7, 6 July 2011, 94
This denarius comes from a small group of rare issues, Crawford 169-172, minted at an uncertain mint circa 199-170 BC. Hoard evidence and overall appearance suggests these issues belong to this period but their bizarre styles and sloppy production suggests they were minted at a mint outside Rome. Even among these issues, this denarius with GR stands out as one of the most sloppily produced types of the entire period and also tends to consistently be found relatively lightweight, with multiple examples even lighter than this one.
It is my belief that these issues were all minted at a military mint in Spain in connection with sporadic military operations, such as those against the Numantines, during this period.