Little round porcelain piece

OK, I know this is kind of a shot in the dark but I figured it couldn't hurt to post this and see if anyone knows what it is. It was in a jewelry box of one of my grandmothers and I don't think it's a glass marble like I played with as a kid. (too big to be a regular marble and too small to be, what we used to call boulders). It feels more ceramic than glass. It's not perfectly round and the blue is on top the white, you can feel it. Plus there are one or two tiny red, yellow and green specks thrown in.
Just wondering if maybe it goes with something else. All comments appreciated.

 

Will be interested in what someone who knows something has to say, but I think it could be a marble. They were not always so standardized in size & seem to have been made all kinds of ways. Who knows? Maybe you have a great rarity there.

 

I'm going to have a look at this myself because I have several marbles that were given to me as a young child by an older man who had them when he was a child. Second section there, right near the top, is about non-glass marbles.

 

Could be an 'end of day' one.

 

Antique marbles were in all shapes,sizes and materials. Its very pretty,Id say it is indeed a marble.

 

Sure looks like one.

 

Googling vintage speckled marbles, and looking at images, brought up quite a few that look like yours, but the few I looked at were described as glass.
Nice!

 

Try robins egg blue glass/ porcelain on google.

 

Well, I guess that settles that, if this many people concur.
I can tell you though, back in the days of playing "potsies", it would have been one weak a$$ shooter. Still own some of the old agates plus some of the one's we called bumble bee's, boy scouts and the red and black one's. (can't remember the name).
Thank you for the input.