Phosgenite

Phosgenite


Composition: Pb2(CO3)Cl2
Crystal System : Tetragonal
Colours: Colourless, white grey, pale-yellow, brown
Lustre : Adamantine, greasy, dull
Hardness (H) : 2.0-3.0
Specific Gravity (S.G) : 6.13

  

Distribution

Very rare. First and second oxidation zones.

Occurrence

  • Supergene
  • 1st Oxidation Zone
  • 2nd Oxidation Zone

Paragenetic and General Notes

Large crystals of smoky-brown phosgenite (ref. a 62 mm single crystal in the Karabacek collection, Harvard University # 93471) were described by Goldschmidt and Thomson (1920), indicating that these were found high in the first oxidation zone, probably between surface and 6 Level. 

Gebhard (1999) describes large etched crystals (to 300 mm) associated with anglesite, cerussite and linarite from the second oxidation zone, most of which were recovered in 1993 (although a single perfect 90 mm crystal from the John Innes collection could be from the same stope, but mined a few years earlier).

Von Bezing (2007) notes that there is some doubt about the origin of the 1993 phosgenite find, with "some rumours" that these crystals are from the Kombat Mine.

The following minerals are reported to form pseudomorphs after phosgenite:  cerussite (rare).