LANGBEINITE

    Class : Sulfates, chromates, molybdates
    Subclass : Anhydrous sulfates
    Crystal system : Cubic
    Chemistry : K2Mg2(SO4)3
    Rarity : Uncommon

Langbeinite is a potassium and magnesium sulfate from marine evaporitic series, commonly associated with halite and sylvite. It can be replaced by kainite. It was named in honor of the German chemist A. Langbein. Langbeinite rarely forms crystals and appears mainly in colorless or white nodules or grains, often slightly tinted grayish, yellowish, greenish or reddish by mineral or clay inclusions. It is occasionally an important potassium and magnesium ore.

Main photo : Langbeinite from Kerr McGee Mine, Carlsbad, New Mexico, USA © Philip Simmons

Langbeinite in the World

Langbeinite is particularly abundant in the Carlsbad deposit (New Mexico) where it constitutes 90% of certain salt beds, sometimes showing 2 cm crystals, the largest known. It is also well represented in the Permian salt deposits of the Stassfurt and Halberstadt region (Germany), and in several other salt deposits throughout the world.

Langbeinite in France

Langbeinite is reported at Avion near Lens (Pas-de-Calais).

Twinning

No twin known for this mineral species.

Fakes and treatments

No fakes recorded for this mineral species.


Hardness : 3.5 to 4
Density : 2,83
Fracture : Conchoidal
Streak : White

TP : Transparent
RI : 1.532 to 1.534
Birefringence : 0
Optical character : None
Pleochroism : None
Fluorescence : Pale green

Solubility : Water

Magnetism : NoneRadioactivity : None