Images
Formula: Ca4Be2+xAl2-xSi9O26-x(OH)2+x (x= 0 to 1)
Inosilicate (chain silicate), multiple chains, forms a series with bohseite
Specific gravity: 2.7
Hardness: 5½
Streak: White
Colour: White
Solubility: Insoluble in common acids
Environments:
Plutonic igneous environments
Pegmatites
Metamorphic environments
Hydrothermal environments
Bavenite occurs as druses in miarolitic cavities in granite and
associated pegmatites, formed by alteration of
beryl and other
beryllium-bearing minerals. Also in hydrothermal veins and
skarn. It often forms
pseudomorphs after
beryl (Dana, HOM). Associated minerals include
beryl, helvine,
phenakite, bertrandite,
quartz, epidote,
stilbite, albite,
orthoclase, titanite,
chlorite, clinozoisite and
tremolite
(HOM).
Localities
At Yaogangxian mine, Yaogangxian W-Sn ore field, Yizhang county, Chenzhou, Hunan, China, a few specimens have been
found of
fibrous crystals of bavenite with topaz and
fluorite
(Minrec 42.6.569).
At Tittling, Passau District, Lower Bavaria, Bavaria, Germany, crystals of
milarite, formed
from the alteration of beryl, have been found with rosettes of bavenite
crystals and bavenite pseudomorphs after
beryl, associated with quartz,
albite and chlorite
(AM 76.1836-1856, Minrec 35.5.408).
Bavenite from Tittling -
Image
At Oberfrauenwald, Waldkirchen, Lower Bavaria, Bavaria, Germany, milarite
crystals occur with quartz, bavenite and
moraesite
(Minrec 35.5.408).
At the Himmelleiten quarry, Roßbach, Wald, Cham, Upper Palatinate, Bavaria, Germany,
milarite
crystals occur in aggregates of fibrous bavenite crystals
(Minrec 35.5.408).
The type locality is the Seula mine, Mount Camoscio, Oltrefiume, Baveno, Verbano-Cusio-Ossola Province, Piedmont,
Italy.
Bavenite from the Seula Mine - Image
At the Kalesay deposit, Ak-Tyuz ore Field, Talas Region, Kyrgyzstan, bavenite occurs with
epidote
(Dana).
At Malyshevo, Sverdlovsk Oblast, Russia, bavenite has been found replacing beryl variety
emerald
(Dana).
Bavenite from Malyshevo - Image
At Shap Pink Quarry, Shap Rural, Eden, Cumbria, England, UK, bavenite has been found
(Mindat photo).
Bavenite from Shap Pink Quarry -
Image
At the gem tourmaline mine at Mesa Grande Mining District, San Diego
County,
California, USA, a 7 cm pseudomorph of bavenite after
beryl has been found, with residual
beryl
embedded
in the bavenite. Considerable albite and smaller quantities of pink
tourmaline, lepidolite and
quartz, and black specks of manganese oxide are partially embedded in the
outside of the
specimen. Much of the bavenite is fibrous
(AM 17.409-422).
In New Hampshire, USA, bavenite is an uncommon mineral found in NYF
pegmatites as translucent, colourless to white crystals
usually less than 3 mm in size, although aggregates to 8 mm have been found. Bavenite forms at pH 8 to 9
(alkaline)
(R&M 97.3.212).
Bavenite from New Hampshire -
Image
At the Stettin pluton, Wausau Intrusive Complex, Marathon Co., Wisconsin, USA, The dike consists of thin upper and
lower
wall zones in contact with weathered amphibole
syenite, upper and lower intermediate zones of
aplite and
pegmatite
bands, and a coarse pegmatitic core zone. In the
aplite band rare grains of bavenite have been found
(R&M 94.2.184).
Back to Minerals