Feinglosite

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...