ECKERMANNITE

    Class : Silicates
    Subclass : Inosilicates
    Crystal system : Monoclinic
    Chemistry : Na3Mg4AlSi8O22(OH)2
    Rarity : Rare

Eckermannite is a rare sodic amphibole of alkaline plutonic rocks, more rarely of alkaline volcanic rocks and nepheline pegmatites. It forms a series with ferro-eckermannite. It was named in honor of the Swedish petrologist and professor Claes Walther Harry von Eckermann. This mineral occurs in glassy masses. It is most of the time colorless.

Main photo : Eckermannite from Hpakant-Tawmaw Jade Tract, Myanmar © Scapin Giovanni

Eckermannite in the World

Eckermannite is known from rare alkaline complexes in Myanmar (Tawmaw) and Japan (Noda-Tamagawa), as well as from nepheline syenites at Norra Kärr (Sweden) and Camp Albion (Colorado).

Eckermannite in France

Eckermannite is not present in the French underground.

Twinning

No twin known for this mineral species.

Fakes and treatments

No fake listed for this mineral species.


Hardness : 5 to 6
Density : 3.02
Fracture : Undetermined
Streak : White

TP : Translucent to transparent
RI : 1.605 to 1.634
Birefringence : 0.029
Optical character : Biaxial -
Pleochroism : None
Fluorescence : None

Solubility : -


Magnetism : None
Radioactivity : None