Odinite
A green iron-bearing member of the serpentine subgroup — a phyllosilicate of ocean-floor and low-grade settings.
Intro adapted from Wikipedia (CC BY-SA).
Odinite is an IMA-recognized mineral species in the silicate class, with the chemical formula (Fe³⁺,Mg,Al,Fe²⁺)₂.₅(Si,Al)₂O₅(OH)₄.
It crystallizes in the hexagonal crystal system (space group Cm). It is a member of the Serpentine, Clay structural group.
Key properties: specific gravity 2.78; Gray-green streak; Silky to earthy luster.
IMA symbol Odn, IMA status: approved, named in 1988.
Formed in marine waters, a minor component of green clay infillings or replacements of microtests, bioclasts, fecal pellets, or mineral debris on shallow marine shelfs and reef lagoonal areas in tropical latitudes.
It is found associated with Quartz, calcite, kaolinite, smectite, illite, chlorite.
The name refers to Dr. Gilles Serge Odin, clay mineralogist of the University P. and M. Curie, Paris, France, who did the initial work on this mineral.