Roger Weller, geology instructor
wellerr@cochise.edu
copyright 2006-R.Weller
Mineral
Information on:
franklinite
Chemical Group: oxide
Chemical Formula: (Fe,Zn,Mn)O.(Fe,Mn)2O3
Color: iron black
Streak: reddish brown or black
Hardness: 5.5
to 6.5
Specific Gravity: 5.07 to 5.22
Fracture: conchoidal to uneven
Cleavage: octahedral parting
Crystal Forms: Isometric
system
Forms octahedrons that are usually rounded
Mineral Associations: willemite, zincite, and calcite
Identifying Characteristics: rounded black octahedrons (almost appears melted)
Uses: zinc ore
Occurrences: Franklin, New Jersey
Toxicity: when-swallowed-
when inhaled-
Additional Information: