Ram\'s Horn Selenite from China

Contributed by: Michael Crawford
Date: Jun 13th, 2025
Locality: Guizhou, China (See on Mindat)
Size: 1 x 11 cm

Description:
A ram’s horn gypsum var. selenite specimen from Guizhou, China. The green fluorescence is activated by uranyl ions. The shortwave emission spectrum of this specimen exhibits vibronic peaks characteristic of uranyl activated fluorescence. The peaks are at 500 nm, 522 nm, 545 nm, 569 nm, and 605 nm.

Fluorescence under shortwave UV light.

Normal light.

Shortwave Emission Spectrum

Summary of luminescence responses:

Gypsum var. Selenite

• Fluorescence under Shortwave (255nm LED) UV light: Green