I've lost my marbles

This is one marble I got from Santa. His little helper said that was made in the early 1900's by Christensen Agate Company. And if it was, then I believe it is called a sandlayer. Santa must have kept it in a box of rocks because it sure was scuffed up. I have polished it and it has turn out to be very pretty to me. Although I am not finished polishing it yet.
If anyone could tell me if this is a real Christensen marble I would sure like to know. I do not think Santa is even sure. It is just under 5/8". It has a diaper fold with a crease line on the other side. And I can see some depth in the dark glass as if it was translusent, but does not show any light through in through though.