Despite tuning down on the Roman coins, I couldn't resist this hefty bronze piece of Faustina. DIVA AVGVSTA FAVSTINA // PIETAS AVG, SC in field. 16.85g; 31.2 mm I'm not quite sure what to make of it though. RIC 1192, so a dupondius? Or 1194; an as? The weight seems to be the closest to the dupondius. Would appreciate if someone could provide me with the correct ID. From the same haul: Syria, Commagene. Zeugma. Philip I. A.D. 244-249. Æ 29 (28.8 mm, 18.62 g, 12 h). AYTO K K M IOYΛI ΦΙΛΙΠΠΟC CЄB, laureate, draped and cuirassed bust right; uncertain countermark / ZЄΓMA-TЄΩN, tetrastyle temple with peribolos containing grove of trees; capricorn right below. This coin is somewhat difficult to photograph due to its glossy brown patina. This is how it looks 'in hand': It probably deserves a thread on its own, however, I lack time to properly write it down. Post any coins you deem relevant!
At first site, I thought Faustina coin is a Sestertius. The second coin has Zeus in the upper temple. The C/M is very common on that coin. I have one.
I had a similar question in the past, also regarding a Faustina bronze. @Roman Collector provided some valuable info here (scroll down the topic) https://www.cointalk.com/threads/trying-to-identify-faustina-i-as.369645/#post-5000194 Since I see the yellowish shade of brass, I think your coin (very nice BTW) would be a Dupondius.
I've been thinking about this one and it's challenging. Its diameter is very large and yet it doesn't quite have the boardwalk flan one might expect if a middle bronze had been struck on a thin, large diameter flan intended for the denomination. This is my version (veiled and stephaned bust) of the coin. Faustina I, AD 138-140. Roman orichalcum sestertius, 28.18 g, 33.1 mm, 6 h. Rome, AD 143-145. Obv: DIVA AVGVS-TA FAVSTINA, veiled and stephaned bust, right. Rev: PIETAS AVG S C, Pietas, veiled, draped, standing left, dropping incense out of right hand over lighted 'candelabrum-altar', left, and holding box in left hand. Refs: RIC 1146Ac; BMCRE 1447-50; Cohen --; Strack 1241; RCV --. The die diameter -- measured from beaded rim to beaded rim across the center, is quite large, 33 mm. The British Museum specimen with the same bust type as the OP is a whopping 34.2 mm in diameter! There is no way the die diameter on the obverse of the OP is 33 mm. It looks more like 30 mm if the coin is 31 mm in diameter. But 30 mm is generous for a middle bronze and the die diameter of the reverse is even larger -- the beaded rim doesn't even fit on the reverse. Here's the dupondius version in my collection (again, I have only the veiled bust version). Faustina I, AD 138-140. Roman orichalcum dupondius, 10.26 g, 27.4 mm, 6 h. Rome, AD 140-41. Obv: DIVA AVGVS-TA FAVSTINA, veiled and draped bust, right. Rev: PIETAS AVG S C, Pietas, veiled, draped, standing left, dropping incense out of right hand over lighted "candelabrum-altar," left, and holding box in left hand. Refs: RIC 1192Ab; BMCRE 1472; Cohen 241; Strack 1241; RCV --. The die diameter is 26 mm, as one would expect. Note, too, this weighs only 10.26 g, whereas the OP coin is 60% heavier. I'm going to say the OP is a SESTERTIUS, based upon the size of the dies, but it's struck on a smaller and light-weight flan. That would make the coin RIC 1146Aa; BMCRE 1442; Cohen —; Strack 1241.
Here is one that is a bit strange - 32 mm but only 13.70 grams (very thin flan). I posted this a while back: https://www.cointalk.com/threads/faustina-i-sestertius-or-dupondius.317204/#post-3092549 Faustina I Æ Sestertius (Struck on dupondius flan?) 3rd Phase, part 2: wedding of Faustina II to M. Aurelius (c. 145-150 A.D.) Rome Mint [DIVA] FAVSTINA, draped bust right / AVGV[ST]A S-C, Ceres standing left with short torch and corn ears. RIC 1118; Cohen 88. (13.70 grams / 32 mm)
I agree with @Roman Collector that its size should make this coin a sestertius rather than a middle bronze. However the coin has a somewhat funny look to me, as though it might be a modern cast with light tooling to strengthen details. That could explain the very low weight for an Antonine sestertius, since a forger can of course raise or lower the weights of his products as he likes.