Willemite and Calcite. Excelsior Claim, Zambia (Africa)

Contributed by: FMS Admin
Date: Feb 28th, 2026
Locality: Excelsior prospect, Chilanga District, Lusaka Province, Zambia (See on Mindat)
Size: 59 x 49 x 77 mm
Weight: 321 g

Description:
Radial brownish Willemite concretions with a 2nd generation growth of white crystals. These fluoresce very bright and willemite has intense and long-lasting green phosphorescence. This particular growth of willemite produces beautiful fluorescence with pretty geometries and contrasts of greens.

Calcite is also present and fluoresces red in SW.

No appreciable fluorescence in MW/LW.

Originally posted by Stefano Buzzoni on Nature's Rainbows.

Fluorescence under shortwave UV light.

Afterglow after exposure to shortwave UV light.

Normal light.

Fluorescence under shortwave UV light. Closeup FOV 20mm

Fluorescence under shortwave UV light. Closeup

Normal light. Closeup

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