While on a hunt last fall, I found the smaller 7/8" diameter marble at the base of a pole, popped it in my pocket and brought it home. My hunting partner that day told me these were used in the boxcars as a means of sliding heavy objects into position when loading or unloading items, and are often found along old lines. A few days later, I had the idea to look through Debbie's awesome marble collection, and to my surprise found the larger 1-1/4" diameter marble! These are characterized by the ice aqua color, and both have some light fizz and heavy straw marks on them. Can anyone else add some information about them; maker, age, etc.? Thanks!