I agree that the curbs are granite. Not marble, tho.
No biggie
I was only leaving open the possibility that my county (the marble capitol of Georgia supplied the marble).
This is where some of our Marble has been used.
The Georgia Marble Company supplied the marble used to build the New York Stock Exchange annex, the statue in the Lincoln Memorial in Washington, D.C., the National Air and Space Museum, the East Wing of the National Gallery of Art, the Federal Reserve Bank in Cleveland, and the Buckingham Fountain in Chicago.
We have a Georgia Marble Festival Every October here. There is an elementary school in Tate that is entirely constructed of white marble. I see driveways lined with crushed marble like it was number 57 granite stone.