Chiavennite with Helvine, Natrolite & Analcime

Availability

Sold

Size

5.5 x 5 x 4 cm - Sm Cabinet 

Formula

CaMn²⁺(BeOH)₂Si₅O₁₃·2H₂O (RRUFF)

Locality

Tvedalen, Larvik, Vestfold, Norway

Tagged

beryllium , pegmatite mineral

A rich specimen of orange, rosette-like crystals of Chiavennite to around .75mm. It is an orthorhombic beryllium zeolite. Outside of the Larvik area, it is only found in 3 or 4 other localities worldwide, all pegmaites.

The Langesundsfjord area hosts some of the world's most mineralogically diverse nepheline syenite pegmatites. The host rock is the silica poor Larvikite, a monzonitic rock, which is used as a local building stone.

This specimen also contains numerous amber colored Helvine (red arrows) crystals to 1mm. I don't think these are Wickmanite or Tetrawickmanite. Zircons are also present as well as tiny colorless Analcime crystals and prismatic Natrolite. It is an excellent specimen.