Marble, granite, and slate were designated as the official state rocks of Vermont in 1991. Vermont has a complex geology with rich and diverse mineral resources. All three of Vermont's state rocks were equally important to the minerals industry that began in the state over 200 years ago.
Marble is found generally in southwestern Vermont (Danby's marble quarry is the largest underground quarry in the world). Vermont marble ranges in color from pure white to black and was used in the National Art Gallery, Radio City Music Hall, the Jefferson Memorial, and Vermont's State Capitol.