JahnsiteFe

JahnsiteFe is an informal or proposed designation for an iron-rich member of the jahnsite phosphate mineral group. It is not listed as a distinct mineral species by major mineralogical authorities such as the International Mineralogical Association (IMA) or widely used databases like Mindat or Webmineral. If used, JahnsiteFe would indicate a solid-solution end-member or a predominance of iron (Fe) in the lattice site that defines jahnsite minerals.

In jahnsite-bearing systems, calcium, iron, manganese, and sometimes other metals occupy related cation sites within a complex phosphate framework. The “Fe” suffix would imply that iron is the dominant metal in the critical site, with other elements present in varying amounts depending on the specific specimen and its formation conditions. The exact chemical formula would thus depend on analytical results from a given sample.

Occurrence of jahnsite-group minerals is typically associated with metamorphic rocks and hydrothermal environments, where phosphate minerals crystallize under varying temperature and fluid conditions. They can occur alongside other phosphate minerals and silicates, and may form as small to medium-sized crystals or masses.

Identification of JahnsiteFe, if used as a formal name, would rely on detailed chemical analysis (for example, electron microprobe data) and structural characterization (X-ray diffraction) to establish iron dominance and confirm its relation to the jahnsite group. Until formally recognized, JahnsiteFe remains a descriptive or provisional label rather than an officially recognized mineral species.

See also: Jahnsite, Jahnsite group, phosphate minerals.