The Quinarius denomination
The quinarius was a small silver Roman coin valued at half a denarius.

Initially, the quinarius was struck for a few years, along with the silver sestertius, following the introduction of the denarius in 211 BC. At this time the quinarius was valued at 5 asses.

The coin was reintroduced in 101 BC as a replacement for the victoriatus, this time valued at 8 asses due to retariffing of the denarius to 16 asses in 118 BC.

For a few years following its reintroduction, large quantities of quinarii were produced, mostly for circulation in Gaul. The coin was produced sporadically until the 3rd century. It was also occasionally struck in gold.
Quinarius
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An AR Quinarius struck 95 (97)BC in Rome
Obverse: laureate head of Apollo right; C·EG(NAT)(VL)EI·C·F / Q

Reverse: Victory left insribing shield on trophy topped with a helmet ornamented with bull horns; carnyx at base of trophy; Q / ROMA

Diameter: -
Die Orientation: -
Weight: -
No notes for this coin
Crawford 333/1, Sydenham 588, RSC I Egnatuleia 1, BMCRR I Rome 1076, Russo RBW 1193, SRCV I 213
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An AR Quinarius struck 101 BC in Rome
Obverse: Laureate head of Jupiter right; C to left.

Reverse: Victory standing right, crowning trophy, beside which stands carnyx; before which, Gallic captive kneeling left; Q (mark of value) in exergue.

Diameter: 14 mm
Die Orientation: -
Weight: 1.76 g
Provenance: CNG Electronic Auction 432 (14 November 2018), lot 244. From the Andrew McCabe Collection, purchased from Peus. Ex Prof. Dr. Hildebrecht Hommel (†1996) and the three-generation Hommel family collection.
Crawford 326/2
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An AR Quinarius struck 88BC in Rome
Obverse: Laureate head of Jupiter right.

Reverse: Victory standing right, crowning trophy; CN LENT in exergue (NT in monogram)

Diameter: 14 mm
Die Orientation: 2 H
Weight: 1.85 g
No notes for this coin
RSC Cornelia 51; Sear 255; Crawford 345/2
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An AR Quinarius struck 88 BC in Rome
Obverse: laureate head of Jupiter right

Reverse: Victory standing right, crowning trophy with wreath; CN LE(NT)

Diameter: 14 mm
Die Orientation: -
Weight: 1.9 g
No notes for this coin
Crawford 345/2, SRCV I 255, Sydenham 703, RSC I Cornelia 5
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An AR Quinarius struck 90 BC in Rome
Obverse: Laureate head of Apollo right, club (control mark) in left field.

Reverse: Victory advancing right, holding wreath and palm-branch, L PI - SO across fields, FRVGI in exergue.

Diameter: 14 mm
Die Orientation: -
Weight: 2.16 g
"Introduced as part of the currency reform of 211 BC, the silver quinarius was initially tariffed at one half of a denarius and five copper asses. Along with the silver sestertius, it ceased to be regularly minted after about 208 BC and was struck only sporadically thereafter. The periodic strikings that did occur were intended to facilitate trade with the Celtic tribes in Gaul and Britain, who seemed to appreciate the coin's small size and even struck their own imitations of Roman quinarii. The issue of L. Piso Frugi in 90 BC complemented that moneyer's enormous output of denarii, which helped finance the Social war raging in Italy."

Provenance: Naville Numismatics, Auction 42 (22 July 2018), lot 422. Ex Sternberg Auction 18 (20 November 1986), lot 323.
Crawford 340/2e
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An AR Quinarius struck 91 (89)BC in Rome
Obverse: head of young Bacchus or Liber right wearing ivy wreath, M·C(AT)O R

Reverse: Victory seated right, holding patera and palm VIC(TR)IX

Diameter: -
Die Orientation: -
Weight: 2 g
The seated figure on the reverse is presumably Victoria Virgo, whose shrine was built by Cato Censorious in 193 BC. -- Roman Republican Coinage by Michael H. Crawford
Crawford 343/2b, SRCV I 248, Sydenham 597a, RSC I Porcia 7b
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An AR Quinarius struck 46 BC in Utica
Obverse: head of Bacchus or Liber right wearing ivy wreath; M·C(AT)O·PRO·PR

Reverse: seated Victory right holding patera and palm; VIC(TR)IX

Diameter: -
Die Orientation: -
Weight: 1.8 g
"This coin was struck under Senate authority in Utica, North Africa where Cato was propraetor at the beginning of the civil war. The design is copied from an issue by another M. Cato in 89 B.C. Cato preferred to die with the Republic rather than outlive it. Defeated by Caesar he committed suicide in 46 B.C." ForumAncientCoins note
Crawford 462/2, SRCV I 1383, Sydenham 1054a,RSC I Porcia 11
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An AR Quinarius struck 42 BC in Lugdunum
Obverse: Winged bust of Victory right, with the likeness of Fulvia; III·VIR downwards in left field; R·P·C upwards in right field.

Reverse: Lion walking right; ANTONI above; A - XLI ( = 41, Antony’s age at time of issue) across field; IMP in exergue.

Diameter: 13 mm
Die Orientation: -
Weight: 1.88 g
Provenance: Numismatik Naumann Auction 73 (6 January 2019), lot 440.
RPC I 513 - Crawford 489/6
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An AR Quinarius struck 27-29 BC in Rome?
Obverse: CAESAR IMP•VII – Head of Octavian.

Reverse: ASIA RECEPTA – Victory draped, standing looking left, holding wreath in right hand. On cista mystica between two snakes

Diameter: 13.5 mm
Die Orientation: 0 H
Weight: 1.45 g

This issue was struck to commemorate that the province of Asia had accepted Octavian's victory over Marcus Antonius in 30 BC. But where Aegyptus was a client kingdom, and therefore could be captured per se, Asia was a veteran province already, so the regular CAPTA reverse was probably deemed unsuitable, and the RECEPTA reverse was used instead.

RIC 276, RSC 14
(10) Octavian
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An AR Quinarius struck 29-27 BC in Rome?
Obverse: CAESAR IMP VII, Bare head of Octavian facing right

Reverse: ASIA RECEPTA, Victory standing facing left, holding wreath and palm, on top of cista mystica, serpents at left and right

Diameter: 15 mm
Die Orientation: 1 H
Weight: 1.66 g
Uncertain Italian mint, probably Rome, maybe Brundisium, Ephesus in Anatolia has also been suggested. RIC finds the later improbable and says it was probably not a mint outside of Rome.

RSC has this to say:

"The subjection of the Province of Asia occurred in B.C. 30."
RIC I (2nd Ed.) Augustus 276; RSC I Augustus 14; BMC 647
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An AR Quinarius struck 211-210 BC in Apulia
Obverse: head of Roma right wearing crested helmet

Reverse: Dioscuri on horses riding right, holding spear and reins, stars over pilei; ROMA

Diameter: -
Die Orientation: -
Weight: 2.1 g
ex UBC Gold und Numismatik
Crawford 102/2d
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An AR Quinarius struck 86 (81)BC in Rome
Obverse: laureate head of Apollo right

Reverse: Victory standing right crowning trophy with wreath; M / ROMA

Diameter: -
Die Orientation: -
Weight: -
No notes for this coin
Crawf. 373/1 b; BMC 757; King 50; Syd. 609 a
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An AR Quinarius struck 94 (98)BC in Rome
Obverse: laureate head of Jupiter right, dot over N

Reverse: Victory standing right, holding wreath and palm. Trophy with Gallic captive seated left, T·CLO(VL)I, Q

Diameter: 0 mm
Die Orientation: 0 H
Weight: 1.9 g

T. Cloulius, supporter of Gaius Marius, struck this issue as questor. This coin commemorates Marius' victory over Teutones in the battle of Aquae Sextiae 102 BC and over Cimbri one year later.

Crawford 332/1b, SRCV I 212, Sydenham 586a, RSC I Cloulia 2a