Hodgkinsonite

Hodgkinsonite Locality: Franklin Mine, Franklin, Franklin Mining District, Sussex Co., New Jersey, USA Dimensions: 4.9 cm x 4.4 cm x 3.2 cm Photo Copyright © Rob Lavinsky & irocks

Chemical Formula: Mn Zn2(SiO4)(OH)2
Locality: Franklin, Sussex Co., New Jersey, USA.
Name Origin: Named for H. H. Hodgkinson, assistant underground supervisor of Franklin mine who discovered the mineral.

Hodgkinsonite is a rare zinc manganese silicate mineral Mn Zn2(SiO4)(OH)2. It crystallizes in the monoclinic system and typically forms radiating to acicular prismatic crystals with variable color from pink, yellow-red to deep red. Hodgkinsonite was discovered in 1913 by H. H. Hodgkinson, for whom it is named in Franklin, New Jersey, and it is only found in that area.

Physical Properties

Color: Light pink, Orange, Reddish brown.
Density: 3.91
Diaphaneity: Translucent to subtranslucent to opaque
Fracture: Brittle – Generally displayed by glasses and most non-metallic minerals.
Hardness: 4.5-5 – Near Apatite
Luminescence: Fluorescent, Long UV=red, weak pink dull dark purple.
Luster: Vitreous (Glassy)

Photo:

This sample of hodgkinsonite is displayed in the Smithsonian Museum of Natural History. The sample is about 20 cm across and is from Franklin, New Jersey.
Franklin Mine, Franklin, Franklin Mining District, Sussex Co., New Jersey, USA © JBS 2006
Hodgkinsonite Location: Franklin, Sussex County, New Jersey, USA. Copyright: © Lou Perloff / Photo Atlas of Minerals