Web site: https://www.ancient-jewellery.com/
This is a nice ancient Roman silver Siliqua of emperor Constantius II struck between 355-360 AD.
Obverse: D N CONSTANTIVS PF AVG "Our Lord Constantius Pious Fortunate August" - pearl-diademed, draped, cuirassed bust right
Reverse: VOTIS XXX MVLTIS XXXX "vows (prayers) on the Thirtieth anniversary (of the emperor's rule), and for his (anticipated) Fortieth anniversary" in four lines within the wreath.
This coin was minted at Arelate (Arles. France) interestingly it had travelled across the English Channel, being found in the East Harptree Hoard in 1887. Coins from this hoard are of exceptional quality and show dark toning. From the East Harptree, Somerset Hoard (found 1887, published by Evans, J. in NC (1888) p. 22-46 and Robertson, A., Inventory of Romano-British Coin Hoards, 1424).
DATE: 337 - 361 AD. (this coin minted between 355 - 360 AD)
MINTMARK: SCON (Arles, France)
SIZE: 18mm diameter
WEIGHT: 1.85 grams
ATTRIBUTION: RIC VIII Arles 207.
PROVENANCE: Originally found in the East Harptree Hoard, Somerset.