Strontianite, Winfield, Pennsylvania

Contributed by: Chris Clemens
minID: CUX-W9T
Date: Apr 24th, 2026
Locality: Winfield, Union County, Pennsylvania, USA (See on Mindat)
Size: 28 x 18 x 37 mm
Weight: 12 g

Description:
Radiating clusters of acicular crystals of off-white colored strontianite from the Winfield Quarry, Winfield, Union County, Pennsylvania. The Winfield Quarry is notable for producing fine quality fluorescent strontianite specimens. This example fluoresces blue/white under shortwave UV and warm white longwave UV. It is also briefly phosphorescent under all wavelengths, most brightly after shortwave UV exposure.

Originally posted by Chris Clemens on Nature's Rainbows in 2016.

Fluorescence under shortwave UV light.

Afterglow after exposure to shortwave UV light.

Fluorescence under longwave UV light.

Normal light.

Summary of luminescence responses:

Strontianite (Mindat) (RRUFF)

• Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: White
• Fluorescence under Longwave (365nm LED) UV light: White
• Afterglow after exposure to Shortwave (254nm Lamp/Mercury) UV light: Blue