Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above
Tillmanns E , Gebert W , Acta Crystallographica, Section B , 29 (1973) p.2789-2794, The crystal structure of tsumcorite, a new mineral from the Tsumeb Mine, S.W. Africa, Locality: Tsumeb mine, Namibia, Africa
Physical Properties of Tsumcorite
Color:
Yellow brown, Reddish brown, Lemon.
Density:
5.2
Diaphaneity:
Translucent
Habit:
Encrustations - Forms crust-like aggregates on matrix.
Habit:
Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)
Habit:
Spherical - Spherical, rounded aggregates.
Hardness:
4.5 - Between Fluorite and Apatite
Streak:
yellow
Optical Properties of Tsumcorite
Gladstone-Dale:
CI meas= -0.087 (Poor) - where the CI = (1-KPDmeas/KC) CI calc= -0.079 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1718,KPDmeas= 0.1731,KC= 0.1592 Ncalc = 1.83
Optical Data:
Biaxial (?), b=1.9, 2V(Meas)=90.
Pleochroism (x):
yellow.
Pleochroism (y):
greenish yellow.
Calculated Properties of Tsumcorite
Electron Density:
Bulk Density (Electron Density)=4.67 gm/cc note: Specific Gravity of Tsumcorite =5.24 gm/cc.
Fermion Index:
Fermion Index = 0.07 Boson Index = 0.93
Photoelectric:
PETsumcorite = 598.06 barns/electron U=PETsumcorite x rElectron Density=2,791.04 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Tsumcorite is Not Radioactive