This is a fossil coral from a Miocene limestone deposit : Peace River, Hardee County, Bone Valley, Hawthorn Group, Florida. This is a Miocene deposit (approx. 5 to 23 million years old).
I cannot identify the exact species type this is. It is a large and robust specimen that is completely mineralized. It measures approx. 6 inches in largest dimension.
Refer to the photos. The centimeter cube is shown for scale and is not included. You are purchasing the specimen shown.