19/32" Vitro Bullseye?

[marblemanvintagemarbles]

It appears to have seams. 

[Fire1981]

That’s a hand faceted agate🔥

RAR

[Al Oregon]

Agree - definitely not Vitro

[Ric]

I agree it looks more like a stone. What does it look like backlit?

[akroorka]

It is a stone agate marble--at first, I thought what a weird Vitro--just not.
Facets are weird little, small flat spots that may appear in hand under a loupe with great light involved and they are very hard to capture regardless of your image processing.
The marks came from the grinder and were left over from the polishing process.
I have managed to catch a few after much try and error. They are all very much the same.
What is weird is that this one saw some play. Notice the little half-moons in the first two images--these are hit marks from play.
 Just a weird looking--desirable old Agate that is more than likely eaten up quite a few glass marbles.

Size is always an issue with ID.
Backlight this one and be rewarded.
Great find!
Marble—On!!