General Information:
Chemical Formula:
Pb2(Zn,Fe)[(As,S)O4]2·(H2O)
Composition:
(Molecular Weight = 751.83 gm)
Zinc 6.52 % Zn
Iron 1.86 % Fe
Arsenic 14.95 % As
Hydrogen 0.27 % H
Lead 55.12 % Pb
Sulfur 2.13 % S
Oxygen 19.15 % O
Empirical Formula:
Pb2Zn0.75Fe2+0.25(AsO4)1.5(SO4)0.5·(H2O)
Environment:
The Zn-dominant analogue of arsenbrackebuschite.
IMA Status:
Approved IMA 1995 (Dana # Added)
Locality:
Tsumeb mine, Tsumeb, Namibia.
Name Origin:
Named after Mark D. Feinglos (b. 1948), Professor at the Duke University Medical Center, Durham, North Carolina, U.S.A., who discovered the mineral.
Physical Properties:
Color:
pale olive green.
Density:
6.52
Diaphaniety:
Transparent
Hardness:
4-5 - Fluorite-Apatite
Luster:
Adamantine
Streak:
white
More details...