This sample of Cumberlandite, a mineral unique to Cumberland, Rhode Island, was transported by glacial movement and deposited in the surrounding landscape. It features a predominantly black surface with subtle brown undertones, giving it a dark, earthy appearance. Scattered across the matrix are flecks of white and silvery crystals—primarily altered plagioclase feldspar—contrasting sharply against the darker groundmass. The texture is coarse and blocky, with a slightly metallic sheen due to the presence of magnetite and ilmenite, which also make the rock weakly magnetic and unusually heavy for its size. These visual and physical traits, along with its historical significance, contribute to Cumberlandite’s status as Rhode Island’s official state rock.