Wavellite from High Down Quarry, England
Contributed by: Michael Crawford
Date: Jul 11th, 2025
Locality: High Down Quarry, West Buckland, North Devon, Devon, England, UK (See on Mindat)
Size: 4 x 7 cm
Description:
Radiating wavellite (Al3(PO4)2(OH)3·5H2O) crystals from High Down Quarry, West Buckland, North Devon, England, are found on a fracture surface of black Codden Hill Chert. The radial clusters can reach up to 2.5 cm in diameter. Wavellite displays white fluorescence under all wavelengths of UV light and shows phosphorescence following exposure to all UV wavelengths. The longwave afterglow exhibits a greenish color. Each cluster contains circular zones that differ in fluorescent intensity, with the outer rim presenting the brightest fluorescence.
The emission spectrum for wavellite under longwave UV has a broad peak centered at 463 nm. An organic activator is considered the probable source of the fluorescence and afterglow.
Summary of luminescence responses:
Wavellite (Mindat) (RRUFF)
- Fluorescence under Longwave (365nm LED) UV light: White
- Fluorescence under Midwave (305nm LED) UV light: White
- Fluorescence under Shortwave (255nm LED) UV light: White