Antoninianus - Probus radiate, cuirassed; AEQVITAS AVG; Aequitas

Reverse

Aequitas, draped, standing left, holding scales in right hand and cornucopiae in left hand.

Scripts: Latin, Greek

Lettering:
AEQVITAS AVG
-/Γ//XXI

Translation:
Aequitas Augusti.
Equity of the emperor.

Comment

This coin is part of the 1st emission of Rome, therefore of the year 276 (Karl Pink, Der Aufbau der römischen Münzprägung in der Kaiserzeit VI/I, Wien, 1949). The coin was minted by the 3rd officina with the Greek letter 'Γ' sometimes as part of the exergue mark (-/-//XXIΓ) and sometimes as right field mark (-/Γ//XXI).

The original RIC text lists two variations, being two bust types (Bust type according to Pierre Bastiens grouping of bust types):
[1] radiate, draped, right (bust type A2), Numista ;
[2] radiate, cuirassed, right (bust type B), Numista N# 293371 (this coin);

For the first variant, RIC only mentions 'draped' and not also 'cuirassed'. Only 'draped' suggests bust type A. See for an example of bust type A from the Rome mint: probuscoins.fr #676 (RIC 240). The examples below suggest that 'cuirassed' was omitted by mistake because the non-B busts are all bust type A2: radiate, draped and cuirassed, right.

Other examples:
- probuscoins.fr #625 (bust B | -/Γ//XXI);
- probuscoins.fr #4385 (bust B | -/Γ//XXI);
- probuscoins.fr #4431 (bust B | -/Γ//XXI);
- probuscoins.fr #1173 (bust B | -/Γ//XXI);
- probuscoins.fr #194 (bust B | -/-//XXIΓ);
- probuscoins.fr #3646 (bust B | -/-//XXIΓ);
- probuscoins.fr #195 (bust A2 | -/Γ//XXI);
- probuscoins.fr #2337 (bust A2 | -/-//XXIΓ).

Mass varies (2.77–4.58 g) and the diameter varies (19,94–23 mm) according to
Online Coins of the Roman Empire (OCRE)

Interesting fact