Nealite

General Information:
 Chemical Formula:
Pb4Fe++(As+++++O4)2Cl4
 Composition:
(Molecular Weight = 1,304.30 gm)
Iron 4.28 % Fe
Arsenic 11.49 % As
Lead 63.54 % Pb
Chlorine 10.87 % Cl
Oxygen 9.81 % O 
 Empirical Formula:
Pb4Fe2+(AsO4)2Cl4
 Environment:
Lead slags.
 Locality:
Laurion, Attica, Greece.
 Name Origin:
Named of Leo Neal Yedlin (1908-1997), micromount mineral collector of New Haven, Conneticut, USA.
Physical Properties:
 Cleavage:
None
 Color:
yellow or light orange.
 Density:
5.88
 Diaphaniety:
Translucent
 Habits:
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline)., Bladed - Aggregates of thin lath-like crystals (e.g. kyanite).,
 Hardness:
4 - Fluorite
 Luminescence:
Non-fluorescent.
 Luster:
Adamantine
 Streak:
light orange
More details...

General Information:
 Chemical Formula:
Pb4Fe++(As+++O3)2Cl4·2(H2O)
 Composition:
(Molecular Weight = 1,308.33 gm)
Iron 4.27 % Fe
Arsenic 11.45 % As
Hydrogen 0.31 % H 
Lead 63.35 % Pb
Chlorine 10.84 % Cl
Oxygen 9.78 % O 
 Empirical Formula:
Pb4Fe2+(AsO3)2Cl4·2(H2O)
 Environment:
Weathered lead slag.
 Locality:
Laurion, Greece.
 Name Origin:
Named for Neal Yedlin (1908-1977), U. S. Mineralogist, who discovered the mineral.
Physical Properties:
 Cleavage:
None
 Color:
bright orange.
 Density:
5.89
 Habits:
Microscopic Crystals - Crystals visible only with microscopes., Bladed - Aggregates of thin lath-like crystals (e.g. kyanite).,
 Luster:
Adamantine
 Streak:
pale orange
More details...