Calcite on pyrite in septaria
Contributed by: FMS Admin
Date: Sep 19th, 2025
Locality: Antwerp, Flanders, Belgium (See on Mindat)
Description:
Yellow calcite skalenohedra on a layer of iridiscent pyrite in septaria, Kontich, Atwerpen, Belgium. The white fluorescence (365 nm LED excitation) is coming from a strong emission in the blue part. Most probably caused by lattice defects, although organic acids are also a possibility since septaria grow in clay close to the surface.
Originally posted by groensteenfreterke on Nature’s Rainbow.
Summary of luminescence responses:
Calcite (Mindat) (RRUFF)
- Fluorescence under Longwave (365nm LED) UV light: White