Chemical Formula: Mn19Zn3(AsO4)3(AsO3)(SiO4)3(OH)21
Locality: Sterling Hill, Franklin, Sussex Co., New Jersey, USA.
Name Origin: Named for J. J. McGovern (1915-), Franklin miner and mineral collector.
History
Discovery date : 1927
Town of Origin : MINE STERLING HILL, OGDENSBURG, SUSSEX CO., NEW JERSEY
Country of Origin : USA
Optical properties
Optical and misc. Properties : Translucent
Refractive Index : from 1,75 to 1,76
Physical Properties
Cleavage: {001} Perfect
Color: Bronze brown, Light brown, Dark reddish brown, Reddish brown.
Density: 3.72
Diaphaneity: Translucent
Fracture: Brittle – Generally displayed by glasses and most non-metallic minerals.
Luminescence: Non-fluorescent.
Luster: Vitreous – Pearly
Streak: brown
Photos :
3(AsO3)(SiO4)3(OH)21 Locality: Sterling Hill, Franklin, Sussex Co., New Jersey, USA. Name Origin: Named for J. J.){kind=link}