Lorenzenite - Encyclopedia
Class : Silicates
Subclass : Inosilicates
Crystal system : Orthorhombic
Chemistry : Na2Ti2Si2O9
Rarity : Rare to very rare
Lorenzenite (formerly called ramsayite) is a rare silicate of nepheline syenites and their pegmatites, exceptionally olivine basalts (Tenerife, Canary Islands). It was named in honor of Johannes Theodor Lorenzen, a Danish mineralogist who was particularly interested in the minerals of Greenland. Lorenzenite occurs in crystals of varied habit : prismatic lamellar to acicular, equant, 6 cm maximum, usually forming fibroradiated to fibrous, lamellar or felted aggregates. The dominant color is brown to black, but purplish, pinkish-gray to pink, even light blue, green, white, gray or colorless shades are also recorded.
Main photo : Lorenzenite from Selsurt Mountain, Lovozersky, Russia © Modris Baum
Lorenzenite in the World
Twinning
No twins known for this mineral species.
Fakes and treatments
No fakes recorded for this mineral species.
Hardness : 6
Density : 3.42 to 3.45
Fracture : Irregular
Streak : White to pale brown
TP : Opaque to transparent
RI : 1.910 to 2.060
Birefringence : 0.120
Optical character : Biaxial -
Pleochroism : Low
Fluorescence : Yellow to green
Solubility : -
Magnetism : NoneRadioactivity : None