Franklinite
Image: Islam90 (CC BY-SA 4.0)
Mineral NameFranklinite
Chemical Formula(Zn,Mn,Fe)(Fe,Mn)2O4
Mohs Hardness6
Crystal Systemcubic
Lustermetallic
Streak Colorreddish-brown
Cleavagenone
Fractureconchoidal
Specific Gravity5.1
Colorsblack, dark reddish-brown
Transparencyopaque
Type LocalityFranklin, New Jersey, USA
Mineral GroupOxides
Usescollector, minor ore
Associated Mineralszincite, willemite, calcite, rhodonite
Rarityuncommon
Description
The image shows a microscopic view of Franklinite, appearing reddish-orange and somewhat translucent under normal light, and dark with a fractured texture under polarized light.
Geological Context
Franklinite is typically found in highly metamorphosed zinc-manganese ore deposits, often associated with marble and skarn environments, famously from the unique deposits in Franklin and Sterling Hill, New Jersey.
