General Information:
Chemical Formula:
Ca2Fe++(Al,Fe+++)2(SiO4)(Si2O7)(OH)2·(H2O)
Composition:
(Molecular Weight = 485.24 gm)
Calcium 16.52 % Ca
Aluminum 11.12 % Al
Iron 11.51 % Fe
Silicon 17.36 % Si
Hydrogen 0.62 % H
Oxygen 42.86 % O
Empirical Formula:
Ca2Fe2+Al2(SiO4)(Si2O7)(OH)·(H2O)
IMA Status:
Approved IMA
Locality:
Langban, near Filipstad, Varmland, Sweden (actually TL of julgoldite).
Name Origin:
Named after the American geologist, R. Pumpelly (1837-1923).
Physical Properties:
Cleavage:
[001] Good, [100] Good
Color:
blue green, olive green, or brown.
Density:
3.2
Diaphaniety:
Translucent
Habits:
Spherical - Spherical, rounded aggregates., Fibrous - Crystals made up of fibers., Massive - Lamellar - Distinctly foliated fine-grained forms.
Hardness:
5.5 - Knife Blade
Luster:
Vitreous (Glassy)
Streak:
white
More details...