General Information:
Chemical Formula:
(Mg7Al2)(Si4Al2)O15(OH)12
Composition:
(Molecular Weight = 834.48 gm)
Magnesium 20.39 % Mg
Aluminum 12.93 % Al
Silicon 13.46 % Si
Hydrogen 1.45 % H
Oxygen 51.77 % O
Empirical Formula:
Mg7Al4Si4O15(OH)12
Environment:
Altered skarn near a copper-gold-silver ore zone. Cr-rich serpentinite.
IMA Status:
Approved IMA
Locality:
Ertsberg East complex, Carstensz Mountains, central Irian Jaya, Indonesia. Wood Chrome mine, Lancaster Co., Pennsylvania, USA.
Name Origin:
For the locality.
Physical Properties:
Cleavage:
[001] Perfect
Color:
colorless, light violet, or light green.
Density:
2.66
Diaphaniety:
Translucent
Habits:
Euhedral Crystals - Occurs as well-formed crystals showing good external form., Platy - Sheet forms (e.g. micas).,
Hardness:
2.5 - Finger Nail
Luminescence:
Non-fluorescent.
Luster:
Pearly
Streak:
white
More details...