I've worked in construction for years. Can't remember exactly when this was, but the job was an old hillside home that had an ancient foundation that had failed, and was sinking into the dirt. we were excavating select areas to pour the new foundation and get the dirt away from the bottom of the house. I found quite a few interesting things on that job, like a few rim-fire large caliber bullet casings, a "Ball" canning jar without the threads for a screw top - just a smooth rim, and a sterling silver teaspoon. And this marble, too. Actually, I think the house was more from 1900 - 1910 now that I think about it. Old, anyway.