So first:
A really HUGE improvement you did there already and this is very good seeing what you come up with now.
I'll give a review now, that actually might be harsh or very critical at some points, but on the other hand if I only say, wow, amazing, it won't help you to improve, so please do not be offended.
The shading you added is very nice and I especially like the fact that you though about how the light would react inside the ring, that's a good start for sure. Also the red diamant in it looks nice already.
Two main issues make this icon still lacking though. First of: The form of the ring. What it needs is "ROUND ROUND ROUND".... YOu can easily see how to create this round ring by googel "ring" or take a look at LOTR's ring
Second one are still the materials. You might want to take a look at my signature, seeing the metal. And you might see, that there are some scratches in it, which always gives your icon a realistic touch (my work could need an improvement there a lot, too, but that's not the point here
I only want to show you, what I mean
) Same goes for the golden part, again this has nice shadings right now, but for me it is tooo yellow.
I'm not sure, if you should continue this icon, because it's quite hard for a start off, very small tracks that you have to draw. I suggest you to see this as a training and to come up with a new icon in which you put all the things you learned while drawing this one. But I can tell you, keep it up, the way you learned the shadowing and the improvement really shows, that you should continue
If you need further help, feel free to ask me