Metal detectorists aren't the only ones who find marbles.I find them when I hunt indian artifacts. I always throw them in an old milk bottle when I get home. I found the milk bottle on a hunt as well. HH Unitas
The large clear (light green) one in the middle looks...
just like the ones I find on RR tracks as I while I am looking for insulators. I've found several like that and read somewhere that some companies transport glass cullet in a marble shape. Don't know the validity of that statement, but it makes sense to me since that is the only place I have found them.
thats right glassyeye...those were made for fiberglass ingots.....it was the most efficient way to transport the glass....one marble contains many yards of the fiberglass.....nice finds unitas