Luster is silky, pearly to earthy. Specimens are translucent. Crystal System is orthorhombic. Crystal Habits include fibrous veins and masses. Cleavage is perfect.
Fracture is uneven.
Hardness is 3 - 3.5. Streak is white. Other Characteristics Non-fluorescent, unlike so many other Franklin minerals. Associated Minerals include franklinite , calcite , pyrochroite and hematite . Notable Occurrence include the type locality of Franklin , Sussex County, New Jersey and Chicagon Mine, Iron County, Michigan, USA and Gonzen Mine, Switzerland.