I dug up this object with a rototiller on a friend of mines lot that he has owned for 40 years. I believe this is made of marble. It is semi polished. The inside threads are tapered. I have given the dimensions below. Please help. LENGTH 3.75" TAPERED WIDTH 2.25" to 1.50" THREADED HOLE WIDTH .75" HOLE DEPTH 1.75" WEIGHT 12oz.