Silver Tetradrachm Ancient Greece 300Bc

If I'm reading the legend it is a Trajan Decius 249-251 AD from the Antioch mint. It's pretty rough and from the appearance of the surface I'm not sure if it's genuine.

Thanks Dwayne! You've got it, I'm sure its a Vespasian Antioch Tetradrachm. Yeah the earlobe looks a bit scratched. I'm pretty sure its genuine, it was found in a field in the South of England and was bundled together in one lot with several other ancient Roman coins that had been found whilst metal detecting. So, according to the auction description, they were part of one man's lifetime collection of field-walking / metal detecting. I'd be pretty gutted if it was fake, as I payed some money for them. In there was a Caraucius Antoninianus though, which I'm very excited about.

Unfortunately, I don't think this Vespasian coin is worth sending to PCGS, but it would be nice to know if it was genuine.

I have quite a large collection of fake ancient coins mainly for educating myself and gaining skill in how to differentiate the various types of fake manufacture, and how to differentiate them from genuine.

I have only pictures to go on here to examine fabric, but I am inclined to think that this piece is genuine.

Unfortunately, weight is not much of a guide on proving authenticty. According to Milne, what is more important is that the coin contained the correct amount of silver in the billon alloy. Billon is a silver alloy with a greater than 50% mixture of copper, usually with a small amount of tin as well.
With this information, an XRF test is indicated to support authenticity.
With the Roman colonial tetradrachms of Vespasian, the total weight of silver only in the coin, should work out to be around three grammes.

Similar tetradrachms of Vespasian in this sort of condition are being offered on VCOINS if the $100 - $200 price range.