Mineral - Bavenite
Bavenite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
Ca₄Be₂Al₂Si₉O₂₆(OH)₂
Unit Cell
a=19.39 b=23.19 c=5.01 Z=4
Physical Properties
Hardness
5.5 - 6
Streak
white
Density
Normal (2-3,5)
Cleavage
Perfect after {001}, distinct after {100}
Fracture
Tenacity
Brittle
Optical Properties
Color
whitecolorless
Birefringence
0.007
Luster
Vitreous,
Silky
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
orthorhombic-pyramidal - mm2
Space Group
Ama2 (40)
Habit
leafy, book-shaped, coarse, acicular, radial, tabular
Formation
Secondary in pegmatites from the alteration of primary beryllium minerals, such as beryl; through metasomatism in skarns
Paragenesis
Twinning
Twins after {100}
Rarity
Rather rare
Synonyms
Bavenite
Composition
Elements
Mass
SiO₂
57.64
Al₂O₃
6.46
BeO
7.66
CaO
23.96
H₂O
3.88
California (Artini 1901)
Name and first discovery: Named after the type locality, near the town of Baveno in Italy. First described in 1901.
Chemism:
Synonyms: Plinite
Varieties:
Abbreviation: Bvn
Literature
Artini, E. (1901). Diuna nuova specie minerale trovata nel granito di Baveno. Rome R. accad. d. Lincei.