Roman coin? [solved]

It is approximately 1.6 centimeters. The color suggests it is made of copper.
Unfortunately I know nothing about the Roman Empire. [This is from the Roman Empire, right?]
Can anyone tell me which Numista entry matches this coin? Also, I'd love to know a little more - enough to be able to look up information about what the images mean, and how it relates to what was going on in the empire at this time.
Thanks!

starting left of the head I can read CONSTANTI - NUS
Beneath the two figures is the mintplace  ?SIC
So please search here, under Constantine (one of the 3)
http://www.wildwinds.com/coins/ric/i.html

The Obverse legend looks to read - CONSTANTINVSMAXAVG
The mintmark is most likely BSIS ( star ) for the Siscia mint.
Using the link Petrus provided search CONSTANTINE II instead ( his son )

That's taken me a lot closer to an answer, but I still need a little help. How much variance is permissible before it isn't the correct coin?
I'm searching for a guy with a straight nose facing right, wearing a headband with circles and ending in beaded lines that don't curve up. The other side has two soldiers with the guy on my right having straighter legs than the ones at the top part of the page, with one standard in-between them, and a mintmark that has an SIC in it.
Could it be this one? http://www.wildwinds.com/coins/ric/constantine_II/_siscia_RIC_VIII_074.jpg
Or maybe this one? http://www.wildwinds.com/coins/ric/constantine_II/_siscia_RIC_viii_085.jpg
Thanks

The mintmark is BSIS *
The 2 links you posted show ASIS & EpsilonSIS
Your not looking for an identical match, just the " type "

Ok... maybe this one? http://www.wildwinds.com/coins/sear/s3952.html
This entry doesn't say a mintmark. The ones that do say a mintmark of BSIS are really different designs.

What makes a coin a similar "type"? How much disagreement is too much? What is critical to be in agreement and what is permissible variance?
Thanks

Hi Pott,
I don't have much time so here goes,
The coin is from SISCIA, I could be wrong but it looks like the letter B before SIS, the other option is E.
What I thought was a star may be a CRESCENT, condition and pictures make it hard to be certain.
The standard appears to have the CHI-RO symbol.
The other diagnostics you can use are the legend breaks,
Your coin has CONSTANTI----NVSMAXAVG & GLOR--IAEXERC--ITVS.
Using this info check wildwinds again - Siscia mint, between RIC VIII 74 & RIC VIII 96.
I will do a more thorough search later on.

Hi NineBobNote,
Here are more pictures under different lighting in case that makes it easier for you to see things
I'll see what I can do with the new clues you gave me too
I really appreciate your help

They are some quality pictures Pott,
There looks to be a crescent with a dot in it which makes your coin SISCIA RIC VIII, 96.
There are 3 varieties for this coin, ASIS, BSIS, ESIS of which yours is either B or E.
The letter before SIS is the mark of the official " officinae " in charge for that period of minting, A=1 B=2 etc.
Along with Wildwinds, www.tesorillo.com is a very good site for learning all about the different types of Late Roman Bronzes.
I used it a LOT when I started out.
Hope this was helpful.

Hi NineBobNote,
Thank you for all the effort you put in to identify my coin. Would you mind helping me just a little more?

I looked for that RIC number under Constantine II, Siscia mint, on the Wildwinds page, but it skips from RIC VIII 92 to RIC VIII 97. I didn't see a 96. It looks similar (to my untrained eye) to RIC VIII 97 - did you mean that one?

I tried to search the Numista catalog so I could mark off the country, but depending how I searched, I either got back results no match, or for other RIC numbers, or it offered me thousands of choices. Is this coin simply not in Numista and that's why I can't find it with a number search? if it is in the catalog, what search words take it to the right coin?

Thank you again

Hi Pott,
Make sure it is www.wildwinds.com you are using, that brings the up to date version on screen.
Just typing wildwinds often brings up the older version which doesn't have the updates, www.constantinethegreatcoins.com is another very useful site for late bronzes including 3rd century as well.
I have never tried to enter any of my ancients into Numista, I wouldn't know where to start as I have so many.
If you post in the Questions section asking how to do it then I am sure someone will guide you through it.
I have just done a quick check for RIC VIII, 97 and it isn't even on the wildwinds page I get, the last entry for SISCIA is 96 !!!
That's an odd 1 indeed.

Hi NineBobNote,
Apparently being on a current version of the website makes all the difference!
I had started with merely assuming it was roman and that's all I knew for around a year. Within a couple of days of asking you, I learned so much more - when and where it was made, and for which emperor, and what images are on the reverse side! I had never even heard of "Chi-roh" before...
Thank you very very much!

Roman coins are my favorites.
A very interesting challenge, but easy to learn. I was a bit confused at the beginning as well.

The most useful tool for me are the excel files from Helvetica´s website.
http://www.catbikes.ch/coinstuff/coins-ric.htm
Download them all, as sooner or later you might need it.

There are many thousands of different roman coins, and therefore Numista catalog not easily follow the RIC book.

Some other useful websites:
http://www.wildwinds.com/
http://dirtyoldcoins.com/roman/legends/indexb.htm
http://www.ancientcoins.ca/RIC/index.htm
http://www.tesorillo.com

There is a EBook that shows all the emperors and most coins - Encyclopedia of Roman Imperial Coins (ERIC)
http://www.dirtyoldbooks.com/eric.html
Very useful book, to have in your smartphone or ipad and to read and see while having some spare time.