Leucophanite and Helvine from Norway
Contributed by: Michael Crawford
Date: Jun 25th, 2025
Locality: Sagåsen Quarry, Sagåsen, Auenlandet, Porsgrunn, Telemark, Norway (See on Mindat)
Size: 5 x 8 cm
Description:
This fluorescent rock comes from the Sagasen (Saga) quarry, Telemark, Norway. The main fluorescent mineral in the rock is leucophanite (NaCaBeSi2O6F). The leucophanite fluoresces violet in longwave, and pink in midwave and pinkish orange shortwave. The leucophanite fluoresces brightest in MW.
The emission spectra measure with various wavelengths of UV illumination indicate that the leucophanite fluorescence is activated by various rare earth elements (REE). Leucophanite has very strong emission in the ultraviolet region when illuminated by midwave and shortwave illumination. There are peaks at 354 nm and 369 nm are caused by cerium replacing calcium. The 462 nm peak in the 405nm spectrum may be caused by europium, dysprosium, or some other REE. Dysprosium is likely activator for the peak at 572 nm in the longwave, midwave and shortwave spectra. The spectra of all wavelengths have a strong peak at 604 nm that is activated by samarium. The small peaks in the 405nm spectrum at 563 nm and 653 nm are probably activated by a REE.
Helvine (Be3Mn2+4(SiO4)3S) occurs as a coating on the face and in fissures in the leucophanite. The International Mineralogical Association (IMA) changed the mineral’s name from helvite to helvine in 2012. The helvite name is more common in literature and older mineral labels. Manual Robbin’s book (1994) describes the occurrence of helvine from the Saga quarry “as yellow crystals in fissures in leucophanite at the Saga 1 quarry at Langesundfjord, Norway” which is the association seen in this specimen. Helvine has bright red fluorescence in longwave UV illumination only. The longwave emission spectrum of helvine has a maximum at 659 nm.
The rock also contains a few grains of fluorite (CaF2) that only fluoresces under longwave UV illumination. The fluorite emission peaks at 421 nm and is activated by europium. There are also grains of calcite that fluoresce red in midwave UV light. The calcite is activated by manganese.
Summary of luminescence responses:
Leucophanite
- Fluorescence under Longwave (365nm LED) UV light: Violet
- Fluorescence under Midwave (305nm LED) UV light: Pink
- Fluorescence under Shortwave (255nm LED) UV light: Orange
- Fluorescence under Longwave (365nm LED) UV light: Red