General Information:
Chemical Formula:
(Zn,Mn++)2Mn++++5O12·4(H2O)
Composition:
(Molecular Weight = 668.48 gm)
Manganese 41.91 % Mn
Zinc 18.59 % Zn
Hydrogen 1.21 % H
Oxygen 38.29 % O
Empirical Formula:
Zn1.9Mn2+0.1Mn4+5O12·4(H2O)
Environment:
Oxidized material derived from the orebody outcrop.
Locality:
Sterling Hill mine, Ogdensburg, Sussex County, New Jersey, USA.
Name Origin:
Named for Samuel Woodruff, late-nineteenth-century miner and mineral collector at Franklin, who collected and preserved many of the finest specimens found at that locality.
Physical Properties:
Cleavage:
None
Color:
brown, iron black, or black brown.
Density:
4.01
Diaphaniety:
Opaque
Habits:
Botryoidal - "Grape-like" rounded forms (e.g.. malachite)., Pulverulent - Forms a loose, poorly-coherent powdery mass.,
Hardness:
4.5 - Between Fluorite and Apatite
Luster:
Earthy (Dull)
Streak:
brownish
More details...