This cross is made from a Black Walnut being cut across in quarter inch slices. The holes are where the nut meat was taken out of the shell. Carefully slice off the ends, that will form the cross, to make them flat and then glue together. It is coated with clear varnish to preserve the finish.
As a young child we picked up black walnuts every fall and took them to the sheller to earn spending money. We picked them up in buckets and then dumped them into huge burlap sacks. Depending on the price of walnuts that year and the weight of our bags was the process that determined how much we were paid.
When black walnuts fall from the trees they have a green/brown outer shell that stains your hands and anything else it touches. We also brought some home and dumped them out in the drive way to drive over and remove the outer shell. Then we would pick them up again and crack the nut with a hammer and pick out the nut meats to use in cooking.
My Aunt Beulah makes the best black walnut brittle you ever put in your mouth. People normally think of peanut brittle, but let me tell you the black walnut brittle is by far the best. She and her husband still pick up black walnuts.