Phosgenite from Monteponi
Contributed by: FMS Admin
Date: Feb 26th, 2026
Locality: Monteponi Mine, Iglesias, South Sardinia Province, Sardinia, Italy (See on Mindat)
Size: 5.7 x 3.6 x 6.5 cm
Weight: 310 g
Description:
Large grey-brown semi-transparent Phosgenite crystals emerge from the galena matrix.
Sample of very low visual impact in daylight due to the fractured and mostly wrapped into the dark matrix crystals. On the other hand, the fluorescence is very bright. Under longwave light, the crystals show a greenish-yellow sheen of non-uniform intensity. This gives character and depth, making the piece non-trivial.
In midwave light, markedly different luminosities and tones are perceived among the crystals.
In shortwave light, however, the response is much less and not worthy of note.
Originally posted by Stefano Buzzoni on Nature's Rainbows.
Summary of luminescence responses:
Phosgenite (Mindat) (RRUFF)
- Fluorescence under Longwave (365nm Lamp/Mercury) UV light: Yellow
- Fluorescence under Midwave (305nm Lamp/Mercury) UV light: Yellow