Geology of Rhode Island

thumb|right|Specimen of cumberlandite on display at the Roger Williams Park Museum of Natural History and Planetarium. Specimen is approximately 1 foot (30 cm) wide. Cumberlandite is a specific type of plutonic rock called a melanocratic troctolite, or melatroctolite. It is the state rock of Rhode Island and can be found in a lot in Cumberland, Rhode Island at Iron Mine Hill. Further traces can be found scattered throughout the Narragansett Bay watershed as far as Martha's Vineyard and Block Island. Cumberlandite is not exclusive to Rhode Island; it is also found in Taberg, Sweden. It is sligh