franklinite
Reference work entry
DOI: https://doi.org/10.1007/978-3-540-72816-0_8856
a mineral of the spinel group. Slightly magnetic. Prized by collectors.
System: cubic.
Formula: 8[(Zn,Mn2+,Fe2+)(Fe3+,Mn3+)2O4].
Luster: metallic to dull.
Colors: iron black.
Streak: reddish-brown to black.
Diaphaneity: opaque.
Cleavage: {111} parting, fair.
Fracture: uneven to subconchoidal. Brittle.
SG: 5.07–5.22.
H: 5½–6½.
RI: 2.36.
Found in Franklin and Sterling Hill, Sussex County, and New Jersey, USA.
Copyright information
© Springer-Verlag Berlin Heidelberg New York 2009