Hulsite is a mineral containing iron, boron and magnesium. It also has tin content. It has the general composition (Fe,Mg)₂(Fe,Sn,Mg)O₂(BO₃). The origin of this sample is Seward Peninsula, Brooks Mountain, Alaska. The sample measures about 10 cm across. The sample is on display in the Smithsonian Museum of Natural History. The hulsite is the black mineral.