Exsolution Willemite, Calcite - Sterling Hill, New Jersey

Contributed by: FMS Admin
Date: May 3rd, 2026
Locality: Sterling Mine, Sterling Hill, Ogdensburg, Sussex County, New Jersey, USA (See on Mindat)
Size: 3 x 2 x 3.5 inches
Weight: 1.8 lb

Description:
A premium example of exsolution willemite in brown tephroite, with calcite, and franklinite from Sterling Hill, New Jersey. Very heavy for its size. We see here striking patterns of willemite exsolution lamellae (collections of fine sheets of material held adjacent to one another). Photographed in SW with a 60mm macro lens at f32 ISO 100.

The pictures below show different views of the specimen.

Originally posted by UV Studio on Nature's Rainbows in 2018.

Fluorescence under shortwave UV light.

Normal light.

Fluorescence under shortwave UV light. Side 2

Normal light. Side 2.

Fluorescence under shortwave UV light. Side 3

Normal light. Side 3

Fluorescence under shortwave UV light. Side 4

Normal light. Side 4

Fluorescence under shortwave UV light. Side 5

Normal light. Side 5

Summary of luminescence responses:

Calcite (Mindat) (RRUFF)

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

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