LAVENITE
Class : Silicates
Subclass : Sorosilicates
Crystal system : Monoclinic
Chemistry : Na2(Mn,Ca,Fe)ZrSi2O7(O,OH,F)2
Rarity : Uncommon
Lavenite is a silicate of alkaline rocks deficient in silica, notably nepheline syenites and their pegmatites, where it accompanies nepheline, eudialyte, titanite, apatite and aegyrine. Its name derives from its discovery location : Laven Island (Norway). Lavenite typically ranges in color from light yellow to black-brown, but can also be exceptionally colorless. When lavenite is not massive, its elongated crystals are frequently united into radiated acicular aggregates measuring up to 2 cm.
Main photo : Lavendulan from Preamimma Mine, Callington, Australia © Jean-Pierre Barral
Lavenite in the World
Twinning
Polysynthetic twins are known on {100}.
Fakes and treatments
No fakes recorded for this mineral species.
Hardness : 6
Density : 3.4 to 3.55
Fracture : Irregular
Streak : Yellow to brown
TP : Translucent to transparent
RI : 1.670 to 1.720
Birefringence : 0.050
Optical character : Biaxial -
Pleochroism : Visible
Fluorescence : None
Solubility : Hydrochloric acid
Magnetism : NoneRadioactivity : None