Mineral - Barnesite
Barnesite
Chemical Properties
Mineral Class
Oxides and Hydrxides
Toxicity
low
Formula
(Na,Ca)V₆O₁₆ · 3H₂O
Unit Cell
a=12.17 b=3.60 c=7.78 β=95° Z=2
Physical Properties
Hardness
3
Streak
red
Density
Normal (2-3,5)
Cleavage
Perfect after {001}, distinct after {100}, {010}
Fracture
Tenacity
Brittle
Optical Properties
Color
red
Birefringence
0.243 - 0.280
Luster
Adamantine
Transparency
translucent,
opaque
Pleochroism
X: Gelb
Y: Orange-Gelb
Z: Rot-Orange
Geomineralogical Properties
Crystal System
monoclinic
Point Group
monoclinic-prismatic - 2/m
Space Group
P2/m (10)
Habit
crusty, acicular
Formation
Oxidation zone of vanadium-bearing uranium deposits
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Barnesite
Composition
Elements
Mass
V₂O₅
82.40
SiO₂
0.40
Na₂O
9.10
H₂O
7.73
Utah (Weeks et al. 1963)
Groups and Members
Hewettite-Group
Name and first discovery: Named after the Canadian crystallographer Howard Barnes (1903-1980). First described in 1963.
Chemism:
Synonyms:
Varieties:
Abbreviation: Bar
Literature
Weeks, A. D., Ross, D. R., & Marvin, R. F. (1963). The Occurrence And Properties Of Barnesite. Na2V6O16-3H2O, A New Hydrated Sodium Vanadate Mineral From Utah. AmericanMineralogist: Journal of Earth and Planetary Materials, 48(11-12), 1187-1195.