I got this really cool stone from a member of Find A Grave who fulfilled a photo request for me. She told me that the marker appears to be petrified wood.
The marker is for George Baylor Allen, my third cousin four times removed. He was born 15 Jun 1844 in Kentucky, the son of John Polk and Georgeann (Baylor) Allen. He died 7 Dec 1910 in Israel Township, Preble Co., Ohio, from morphine poisoning, and is buried in Hopewell Cemetery, Morning Sun, Preble Co., Ohio. He married Anna M. Robinson in 1871 and they had five children: Mayme, George Baylor Jr., Florence, Theodore and Carter. He was a Civil War veteran.