Mineral - Baumstarkite
Baumstarkite
Chemical Properties
Mineral Class
Sulfides and sulfosalts
Toxicity
none
Formula
Ag₃Sb₃S₆
Unit Cell
a=7.77 b=8.32 c=8.81 α=101° β=104° γ=90° Z=2
Physical Properties
Hardness
2.5
Streak
blackgraygray black
Density
Heavy (3,5-6)
Cleavage
Perfect after {001}
Fracture
Tenacity
Supple
Optical Properties
Color
blackgraybronze
Birefringence
Luster
Metallic
Transparency
opaque
Pleochroism
Geomineralogical Properties
Crystal System
triclinic
Point Group
triclinic-pinacoidal - 1
Space Group
P 1 (2)
Habit
spherical
Formation
In hydrothermal ore deposits
Paragenesis
Twinning
Twins after {001}
Rarity
Very rare
Synonyms
Baumstarkite
Composition
Elements
Mass
Ag
36.30
As
0.70
Sb
40.20
S
22.00
Peru (Effenberger et al. 2002)
Name and first discovery : Named after the German mineralogist Manfred Baumstark (1954). First described in 1999.
Chemistry : Polymorph with cuboargyrite and miargyrite
Synonyms :
varieties :
Abbreviation: Bum
literature
Effenberger, H., Paar, WH, Topa, D., Criddle, AJ, & Fleck, M. (2002). The new mineral baumstarkite and a structural reinvestigation of aramayoite and miargyrite. American Mineralogist , 87 (5-6), 753-764.