General Information:
Chemical Formula:
(Mn,Zn)9(SiO4)4(OH)2
Composition:
(Molecular Weight = 902.02 gm)
Manganese 51.77 % Mn
Zinc 3.62 % Zn
Silicon 12.45 % Si
Hydrogen 0.22 % H
Oxygen 31.93 % O
Empirical Formula:
Mn2+8.5Zn0.5(SiO4)4(OH)2
Environment:
Metamorphosed Zn-Mn deposit. Dimorphous with sonolite.
IMA Status:
Approved IMA
Locality:
Franklin mine, Sussex County, New Jersey, USA.
Name Origin:
Named for Gerald V. Gibbs (1929-), Virginia Polytechnic Institute, Blacksburg, Virginia, USA.
Physical Properties:
Cleavage:
[001] Imperfect
Color:
violet pink.
Density:
4
Diaphaniety:
Transparent to Translucent
Habits:
Massive - Granular - Common texture observed in granite and other igneous rock., ,
Hardness:
5.5 - Knife Blade
Luminescence:
Non-fluorescent.
Luster:
Vitreous (Glassy)
Streak:
light pink
More details...