Bavenite - Encyclopedia

    Class : Silicates
    Subclass : Inosilicates
    Crystal System : Orthorhombic
    Chemistry : Ca4Be2Al2Si9O26(OH)2
    Rarity : Fairly common

Bavenite is a secondary beryllium silicate present in the vacuoles of granites and granitic pegmatites, where it is formed by weathering of beryl. More rarely, it is found in alkaline syenite skarns (Ilimaussaq, Greenland), as a product of helvite alteration, and in hydrothermal veins. It is evident a usual companion of primary beryllium silicates, especially beryl. Its name comes from its locality of discovery : Baveno, near Lake Maggiore (Italy). The crystals are elongated prisms united in radial aggregates reaching 6 cm, lamellae grouped in rosettes or needles assembled in fibrous to compact aggregates ; bavenite also forms masses of chalky appearance. It is a colorless to white mineral, sometimes slightly reddish, greenish or light brown.

Main photo : Bavenite from Seula mine, Mount Camoscio, Oltrefiume, Baveno, Piedmont, Italy © Gianfranco Ciccolini

Bavenite from Baveno, Piedmont, Italy © Chinellato Matteo
Bavenite from Foote, North Carolina, USA © Jason B. Smith
Bavenite from Foote, North Carolina, USA © Martin Slama
Bavenite from Old Mine Plaza Connecticut, USA © David Busha

Bavenite in the World

The largest known crystals, forming groups of 6 cm, come from Russia, Akoudertia (Siberia) and Malishevo (Urals) ; in this second locality, bavenite occasionally replaces emerald crystals. Beautiful bavenite pseudomorphs after beryl crystals are known in several localities of Moravia (Czech Republic), and in the lithium pegmatites of the Himalayas, near Mesa Grande (California). Beautiful crystals of bavenite have also been discovered in the lithiniferous pegmatite of Foote (North Carolina), in the Waterville Valley (New Hampshire), and at Baveno (Piedmont, Italy).

Bavenite in France

In France, bavenite has been described at the Gwernavalou quarry near Trémargat (Côtes-d'Armor).

Twinning and special crystallizations

Twins are known on {100}.

Fakes and treatments

No fake or treatment identified for this mineral species.


Hardness : 5.5
Density : 2.7
Fracture : Irregular
Trace : White

TP : Translucent to transparent
RI : 1.578 to 1.593
Birefringence : 0.005 to 0.007
Optical character : Biaxial +
Pleochroism : None
Fluorescence : None

Solubility : Insoluble

Magnetism : None
Radioactivity : None

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