Roman Antoninianus Coins, Authenticated Third-Century Silver and Billon

The antoninianus is the silver — and then billon — coin Rome turned to when the denarius could no longer pay the army. Caracalla introduced it in AD 215 as a doubled denomination, valued at two denarii but containing only about 1.5 denarii of silver. From that moment, the antoninianus was a debasement instrument. By the reign of Gallienus (AD 253-268) the silver content had collapsed to under five percent. By Aurelian's reform in AD 274, the coin survived only as a copper core with a silver wash. It was abolished by Diocletian's monetary reform in AD 294, ending an eighty-year experiment in inflationary coinage.

This collection is Aurora's current stock of antoniniani — four authenticated examples spanning Philip I, Gordian III, Probus, and the wider third-century Crisis-period mints. Each is RIC-referenced, photographed obverse and reverse at 2,048 pixels, independently reviewed by a numismatist, and backed by Aurora's written lifetime authenticity guarantee.

Why antoniniani matter to a collector

Antoniniani sit at one of the most volatile moments in Roman monetary history — the so-called Crisis of the Third Century (AD 235-284). The coin is the metallic witness to the empire's near-collapse: barbarian invasions on multiple frontiers, economic dislocation, hyperinflation, civil wars, and a procession of short-reigned emperors who appear on these coins and then vanish from history. Holding an antoninianus of Philip I, killed by Decius in AD 249, or Probus, murdered by his own troops in AD 282, connects directly to that instability.

The denomination is also identifiable at a glance by the radiate crown: a circle of sun-rays around the emperor's head, signalling the doubled denomination. For empresses, the equivalent marker is the crescent moon below the bust. The radiate crown is the antoninianus's signature feature — see the full denomination guide for context.

What to check on an antoninianus

Three signals separate a collectible antoninianus from a worn or problematic one. The radiate crown should be sharp — the sun-ray points crisply incised, not smeared. The portrait should match documented die-style for the named emperor (the third-century crisis emperors have brutal, frontal, schematic portraits that are unmistakable once learned). The reverse should match a published RIC type; Aurora's catalogue references the relevant entry on every listing.

Weight for a Caracalla-to-Severus-Alexander antoninianus: 3.0 to 5.0 grams of nearly-pure silver. By the 250s, weight drops to 2.5 to 3.5 grams at 30-40 percent silver. By the 270s, 2.0 to 3.0 grams with only trace silver under a thin surface wash. The wash, when present, often wears off on circulated examples — exposing the copper core is normal, not a flaw. The full check is in our guide on how to authenticate an ancient Roman coin.

Why buy an antoninianus from Aurora

Two reasons. First, the work done before the coin reaches the listing page: seven antiquarian markers, RIC reference confirmed, OCRE cross-reference, independent numismatist sign-off. Second, the written lifetime authenticity guarantee — if an antoninianus from Aurora is ever shown to be inauthentic, we refund the full purchase price, without time limit.

All four antoniniani in this collection ship insured worldwide from Belgium with provenance documentation. For the broader Roman silver range, see the full Roman coin catalogue. For the wider Severan dynasty silver, see the Severan dynasty coin collection.