Marble collectors used to call this marble a "Miller".
Big bucks for a minty one. Yours, in mint shape would have have delivered in a great way dollar wise.
Nice find--a good place-holder for anyone that collects these.
Marble--On!!
The first one is a Rainbo my marble collecting friend--a very nice one.
The second one is a MCS or multi colored swirl--another nice one.
You can alway get more opinions from @Ric @Chad G. or @Fire1981 and I welcome them all as well as those from anyone willing to give an ID here.
Marble--On!!
I like it!
It may have been one of those that rolled down the cold air exchange and into the fire below.
Furnace folks used to find these quite frequently.
I does look like a Silver Oxblood from Akro--just bit by fire (coal or gas) a bit.
Marble--On!!
Agreed--Pretty cool with all of the lumps and folds involved.
My money is on this one being a Veiligglas marble.
@Mojo , @Ric and @Chad G. may have an opinion here as well.
I appreciate all opinions and hope to see some more.
Nice find!
Marble--On!!