Clear shooter marble with a black,blue and gold colored duck

[Rhonda]

I found this in my moms rock and marble garden. I have not been able to find 

Another one like it.

Does anyone know about this type of marble

[Steph]

There are old marbles with white figures inside which can look a little silvery because of the air trapped around them (I think).  The modern name for that old style of marble is "sulfide".

And there are modern marbles made with figures inside.  

I have very little experience with either of them.  I don't know of any that look as silver as yours does.