Fake or real silver roman coin?

[mcrfuse]

Yesterday I bought a roman silver coin from a dealer near me, I don't really know much about them but I wanted to have one for my collection. I went online and did some research. I understand that roman silver coins had a set weight to them, but mine is over weight? It's suppose to weigh 3.5-3.8 grams but mine weighs 5 grams. I did the magnet test on it ad it seems fine, there are a bunch of cracks near the edge and I can no sign of copper. Is it normal for roman silver coins to weigh that much over?
PHILIP I, antoninianus - PHILIPPE Ier L'ARABE (244-249) Antoninien, Rome 247 | eBay