Roman Provincial Tetradrachm? [επιλυμένο]

I think this is a Tetradrachm but I don't know, I could not find it on the site, I found similar coins, just not exact, I do not know what it is made of as of yet, any help will be appreciated, Thanks!

Hello,

It is indeed a billon tetradrachm struck in Alexandria during the 3rd century, during the 1st year of the reign of the emperor on it (L A on reverse). The reverse shows Tyche standing left holding rudder and cornucopia.
The emperor is Carinus. I had trouble at first because I read "MAKPINOC" but Macrinus don't look like this at all. But it was actually "M A KAPINOC"!
Reference is Milne 4669.
http://www.wildwinds.com/coins/ric/carinus/milne_4669.jpg
http://www.wildwinds.com/coins/ric/carinus/milne_4669.txt

It's a very nice coin you got, with good details, well struck and some interesting blue stuff on it.

Thank you Choucas!
I am glad it is real, but as far as this site, I have yet to find it and if I do need to add it myself, well this is all new to me and I do not want to make a mess of it, I have no scale to weigh it at this time, I have one being delivered next week, hopefully if all goes well it will give me an accurate weight
PS. I have several more I will be asking about, so I hope you are able to help with them also, ancient coins are very difficult for me to identify correctly, and to me that's the most important thing to do
Thanks again!

oh I forgot, the interesting blue stuff, I'm according to my eye doctor, color deficient, blue is hard for me to see
I figure, it's probably been on there for a while, I'm guessing it hasn't hurt it

Not sure what is the name of the blue crystals : Azurite maybe ?

I got some roman era coins with this kind of crystallization this month. The most impressive was probably this one : https://fr.numista.com/catalogue/pieces155287.html

I assumed the green could be brochantite while the blue could be azurite / linarite (or something else ?).

Could the green be malachite ? Malachite and azurite often come together. I'm not sure.

Indeed, it could be.
I don't have much knowledge in this area unfortunately