Old Roman coin to identify.

Here's what I've gathered so far but can't find much more info.  The reverse from what it appears is a snake,  i did some research and found its called the snake cult of alexander. I read up a little on it, but can't find which rulers had that on the reverse to match and identify it. Any help would be greatly appreciated. I do know it's roman in suspecting from the year 120 to the 240ish AD. I could be wrong on that

Hello.

How do you know that it is roman? Doesn't really look like one to me. 
The bust only has the contours in relief (is stylized), whereas on roman coins the bust is entirely in relief.

Of course, without size (including thickness) and weight it's just guesswork.
I can't use your (leg?)hair as a reference.

😂I kept putting it on different surfaces and the coin would turn dark.  It'sthe size of a quarter. I tried researching and found a type of reverse type called the “snake cult of alexander”.I keep seeing the same 3 or 4 obverse images and can't find references. I use torillo.com but didn't see it there.  I'll try and take better photos. 

The outline I've never seen either on roman coins. It's a gold color. 

Rickthetreasurehunter

😂I kept putting it on different surfaces and the coin would turn dark.  It'sthe size of a quarter. I tried researching and found a type of reverse type called the “snake cult of alexander”.I keep seeing the same 3 or 4 obverse images and can't find references. I use torillo.com but didn't see it there.  I'll try and take better photos. 

So the size of a quarter. 

Is the diameter about that of a Moolah? Or more like a half fuseodollar?

What is the weight in terms of Dr. Pepper cups?

Could you see if the coin is scratched by a fluorite crystal?

Alternatively, you could provide the size, thickness and weight in a unit of measurement other than bodily parts or random objects only found in the US.

 

Cheers 😁

SPQR

 

So the size of a quarter. 

 

A US quarter has a diameter of 24.26 mm.

Any help would be greatly appreciated.