Multi-Colored Sphalerite - Balmat No. 4 Mine, Balmat, New York

Contributed by: Chris Clemens
minID: GN3-D9U
Date: May 24th, 2026
Locality: Empire State No. 4 Mine, Balmat, Fowler, St. Lawrence County, New York, USA (See on Mindat)
Size: 11.6 x 4.25 x 15.8 cm
Weight: 658 g

Description:
Large, triangular-shaped piece of metallic grey colored sphalerite/zinc ore with brassy grains of an unidentified sulfide mineral (pyrite or chalcopyrite), from the ZCA Mine No. 4 (now called the Empire State No. 4 Mine), Balmat, St. Lawrence County, New York. This specimen shows a beautiful, moderately bright, multi-colored fluorescent response under longwave and shortwave UV. This material is sometimes referred to as "birdseye sphalerite" or "birdseye ore".

Originally posted by Chris Clemens on Nature's Rainbows in 2022.

Fluorescence under longwave UV light.

Afterglow after exposure to longwave UV light.

Fluorescence under shortwave UV light.

Afterglow after exposure to shortwave UV light.

Normal light.

Summary of luminescence responses:

Sphalerite (Mindat) (RRUFF)

• Fluorescence under Longwave (365nm Lamp/Mercury) UV light: Green
• Fluorescence under Longwave (365nm Lamp/Mercury) UV light: Orange
• Afterglow after exposure to Longwave (365nm Lamp/Mercury) UV light: Green
• Afterglow after exposure to Longwave (365nm Lamp/Mercury) UV light: Pink
• Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Orange
• Afterglow after exposure to Shortwave (254nm Lamp/Mercury) UV light: Green
• Afterglow after exposure to Shortwave (254nm Lamp/Mercury) UV light: Orange