Ferrisicklerite - Encyclopedia
Class : Phosphates, arsenates, vanadates
Subclass : Anhydrous phosphates
Crystal system : Orthorhombic
Chemistry : Li(Fe,Mn)PO4
Rarity : Rare
Ferrisicklerite is the iron-bearing pole of a series that it constitutes with sicklerite ; it has been considered since 2022 as a variety of triphyllite. It is a rare secondary phosphate formed by hydrothermal or meteoritic alteration of primary phosphates (triphyllite, lithiphyllite, etc...) in granitic pegmatites. The crystals are rare, forming individuals of 1 cm maximum, gathered in radiate or spherical aggregates. Ferrisicklerite is generally massive, in nodules or rings of alteration around masses of triphyllite - lithiphyllite. It is yellow-brown to dark brown in color.
Main photo : Ferrisicklerite from Palermo N°1 Mine, New Hampshire, USA © Andrew Hodgson
Ferrisicklerite in the World
Twinning
No twin known for this mineral species.
Fakes and treatments
No fakes recorded for this mineral species.
Hardness : 4
Density : 3.2 to 3.4
Fracture : Irregular
Streak : Brown
TP : Opaque
RI : 1.790 to 1.820
Birefringence : 0.021
Optical character : Biaxial -
Pleochroism : Visible
Fluorescence : None
Solubility : Acids
Magnetism : None
Radioactivity : None