Mineral - Balangeroite
Balangeroite
Chemical Properties
Mineral Class
Silicates
Toxicity
high
Formula
(Mg,Fe²⁺,Fe³⁺,Mn²⁺)₄₂Si₁₆O₅₄(OH)₄₀
Unit Cell
a=19.40 b=9.65 c=19.40 β=91° Z=2
Physical Properties
Hardness
3 - 4
Streak
white
Density
Normal (2-3,5)
Cleavage
Perfect after many {hkl}
Fracture
fibrous
Tenacity
Brittle
Optical Properties
Color
browngreengold
Birefringence
0,000
Luster
Vitreous
Transparency
translucent,
opaque
Pleochroism
X: Braun-Schwarz
Y: Gelb-Braun
Geomineralogical Properties
Crystal System
triclinic , monoclinic
Point Group
triclinic-pinacoidal - 1 , monoclinic-prismatic - 2/m
Space Group
P 1 (2)
Habit
fibrous
Formation
Through metasomatism in serpentinites
Paragenesis
Twinning
Rarity
Very rare
Synonyms
Balangeroite
Composition
Elements
Mass
SiO₂
28.37
TiO₂
0.03
Al₂O₃
0.27
Fe₂O₃
8.89
Cr₂O₃
0.03
FeO
16.95
MnO
3.59
MgO
31.81
CaO
0.13
H₂O
9.93
Italy (Compagnoni et al. 1983)
Name and first discovery: Named after the type locality, which is near the town of Balangero, Italy.
Chemism: Balangeroite possibly has several polytypes (2M, 1A) (Bonaccorsi et al. 2012)
Synonyms:
Varieties:
Abbreviation: Bal
Famous locations
(TL) Type locality (analysis) Chemical element distribution, see above
Italy
(TL) (Analysis) Poggio San Vittore Asbestos Mine, Balangero, Piedmont, Italy
Literature
Compagnoni, R., Ferraris, G., & Fiora, L. (1983). Balangeroite, a new fibrous silicate related to gageite from Balangero, Italy. AmericanMineralogist, 68(1-2), 214-219.