Barite, Calcite and Franklinite - Sterling Mine, Sterling Hill, New Jersey

Contributed by: Chris Clemens
Date: Apr 28th, 2026
Locality: Sterling Mine, Sterling Hill, Ogdensburg, Sussex County, New Jersey, USA (See on Mindat)
Size: 23.7 x 16.3 x 38 mm

Description:
This is a large-grained rock containing light, grey-colored calcite and barite, and black franklinite crystals; a much sought after mineral assemblage from the Sterling Mine, Sterling Hill, Sussex County, New Jersey. Under shortwave UV the calcite fluoresces red/orange and the barite white. The Franklinite is not fluorescent.

Originally posted by Chris Clemens on Nature's Rainbows in 2017.

Fluorescence under shortwave UV light.

Normal light.

Summary of luminescence responses:

Baryte (Mindat) (RRUFF)

• Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: White

• Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Red