Cumberlandite is a black or dark brown mineral with white flecks on it, believed to have been created by volcanic activity approximately 1.5 billion years ago, by geologists. It is one of very few naturally occuring magnetic minerals, based on it's high ferrous content, and can only be found in central Rhode Island, between the town of Cumberland and the rim of the Narragansett Bay. This stone was called Rhodose until 1966, when it was renamed by the state of Rhode Island, based on it's unique nature. Also of note is that this stone is considered sacred by the tribe of the Nipmuk, located across northern Rhode Island and Massachusetts.