Unusual Fluorite from the Huanzala Mine, Peru

Contributed by: Michael Crawford
Date: Jun 1st, 2026
Locality: Huanzala Mine, Huanzala, Huallanca District, Bolognesi Province, Ancash, Peru (See on Mindat)
Size: 4 x 5 cm

Description:
This specimen has light lavender fluorite crystals nestled within white calcite crystals on a matrix of pyrite. The specimen comes from the Huanzala Mine, Peru. The fluorite fluoresces the typical blue color under longwave UV light as shown in the longwave emission spectrum below. However, under midwave UV light, the outer rims of the fluorite cubes fluoresce green, and the interior of the cubes retain the blue fluorescence. The fluorite cube fluorescence is all green under shortwave from the bright green fluorescence of the fluorite rims.

Green fluorescence is unusual for fluorite. Fluorite from Fourmile Creek in Colorado and the Ojuela Mine has green fluorescence under shortwave light. The green fluorescence is activated by uranyl ions as indicated by the emission spectra shown below. I could only get noisy spectra from the rims of the Huanzala fluorite. There are sharp peaks in the shortwave spectrum to suggest that uranyl ions activate the green fluorescence.

Calcite fluoresces under longwave and midwave light. It is brightest under midwave and there is no calcite fluorescence under shortwave.