This appears to be a Hexagonaria sp. coral fossil. It was probably found in the Jeffersonville Limestone of Jefferson County, Kentucky or Clark County, Indiana, USA. These animals existed in the Devonian Period.
This fossil is part of a very unique fireplace exist in a house in the city of Louisville Kentucky, USA. It was created by local geology professor from various fossil finds throughout his lifetime. I took a number of pictures of it and will blog about them in the near future.
