EDENITE
Class : Silicates
Subclass : Inosilicates
Crystal system : Monoclinic
Chemistry : NaCa2Mg5(Si7Al)O22(OH)2
Rarity : Uncommon
Edenite is a sodium, calcium and magnesium amphibole, formerly considered a variety of "hornblende". It is now recognized as a mineral in its own right and forms a continuous series with ferro-edenite, its iron-bearing equivalent. It is an uncommon amphibole, especially present in metamorphic limestones and dolomites, particularly marbles. It is probably quite widespread but its precise identification requires significant analytical means, not always accessible to amateurs. It owes its name to its presumed location of discovery : Edenville (New York). Edenite occurs in prismatic crystals, often stocky with a hexagonal section, rarely doubly-terminated. It is also common in masses or aggregates that are more or less fibrous to bacillary, sometimes grainy. The color is usually green-black to black.
Main photo : Edenite of Monmouth Township, Highlands East Township, Haliburton County, Ontario, Canada © John Sobolewski
Edenite in the World
Twinning
Single or multiple twins are known on {100}.
Fakes and treatments
No fake listed for this mineral species.
Hardness : 5 to 6
Density : 3.05 to 3.37
Fracture : Irregular
Streak : White to gray
TP : Translucent
RI : 1.606 to 1.672
Birefringence : 0.025
Optical character : Biaxial +
Pleochroism : Visible
Fluorescence : None
Solubility : Insoluble
Magnetism : None
Radioactivity : None