Hello everyone, today I have a question about how I should proceed with cleaning this coin which I assume is greek(weighs 2.18 grams). As you can see in the photo below it has a thick layer of dirt covering most of it but on the obverse
on the left side
there seems to be some color sticking out. It look silverish with dark green spots on it which might be malachite deposits. So any responses on how to proceed would be much welcomed, because if this is greek it is my first one uncleaned.