Buergerite - Encyclopedia

    Class : Silicates
    Subclass : Cyclosilicates
    Crystal system : Rhombohedral
    Chemistry : NaFe3Al6(BO3)3Si6O18(O,F,OH)4
    Rarity : Very rare

Buergerite, recently renamed fluor-buergerite, is the rarest of the tourmalines. It was named in honor of crystallographer Martin Julian Buerger, professor of mineralogy at MIT. It is a mineral of hydrothermal origin, like the other minerals of the group, it forms short to elongated, strongly fluted prismatic crystals, measuring up to 4 cm, frequently united in radiating groups. It is dark brown to black in color.

Main photo : Fluor-buergerite from Mexquitic from Carmona Municipality, San Luis Potosí, Mexico © Kevin Conroy

Buergerite in the World

Buergerite is known only from Mexquitic (Mexico) in the cavities of a rhyolite associated with biotite, feldspar and quartz.

Buegerite in France

Buergerite is not present in the French underground.


No known twin for this mineral species.

Fakes and treatments

No fake identified for this mineral species.

Hardness : 7
Density : 3.3
Fracture : Conchoidal
Streak : Light brown

TP : Translucent to opaque
RI : 1.655 to 1.735
Birefringence : 0,080
Optical character : Uniaxial -
Pleochroism : Visible
Fluorescence : None

Solubility : Insoluble

Magnetism : None
Radioactivity : None


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