Rodrian is cited as the source of a specimen of Tsumeb
phosgenite.
This reinforces the earlier conclusion [25], based on the fact that the natural abundance is very rare and by recipes found in ancient Egyptian texts, that the laurionite had been prepared synthetically, as was
phosgenite, ([Pb.sub.2][Cl.sub.2][CO.sub.3]), another ingredient found in some powders.
But, notwithstanding the beauty and rarity of the many discoveries he made elsewhere, Wright's finest hour as a collector-dealer was his discovery in 1851 of
phosgenite and of the new mineral matlockite in the Bage mine at Cromford in Derbyshire.
1166 Laurionite and
Phosgenite, Laurium, Greece, no.
Right next to it was a selection of rare
phosgenite crystals from Monteponi, Italy.
The Colorado Geological Society of Denver had a very fine display featuring a rare
phosgenite and some of Colorado's pretty pink rhodochrosites.
The Arizona-Sonora Desert Museum put in an elegant display of Tiger mine minerals, rare lead silver sulfosalts, wulfenite, dioptase and a very rare
phosgenite. The Royal Ontario Museum from Toronto displayed some superb phosphates.
And the Natural History Museum of Milano, Italy gave everyone a treat with a display of some of the world's better lustrous
phosgenite crystals.
I found a very large, almost 3-kg piece of
phosgenite. It was broken into three pieces, one of which is still somewhat okay as a specimen; the two large pieces have very large clear areas for faceting in them, so I purchased these for [euro]700.
Of special interest were two cases of "rarities" from Colorado; it is indeed rare, and of course educational, to see fine Colorado specimens of, for example, allanite, bismuthinite, chrysoberyl, chlorargyrite, and
phosgenite. Of individual specimens fine and surprising enough to make me reach for my pen and notepad at the very first glimpse, I'll mention a foot-wide group of spiky white cerussite crystals from the Bulldog mine; a couple of just-as-giant matrix specimens of Book Cliffs bari te, with vivid colorless prisms to 8 cm long on both; a handful of specimens of zircon from St.
The contents were scattered over several meters around: vesuvianite (from Bellecombe, Aaosta Valley?), epidote (from Antronapiana, Ossola Valley?), zeolites (from Fassa Valley?), stibnite (from the Cetine mine in Tuscany?), galena and
phosgenite (from Monteponi, Sardinia?), sulfur (from Sicily?), and so on.
For example, the earlier texts only briefly mention Tsumeb
phosgenite, as it was earlier known only in a few negligible specimens; but here we read of a 1993 pocket, in the third oxidation zone, which produced the world's finest
phosgenite crystals, and to prove the claim there is a full-page photo of a gemmy brown, perfectly formed 9-cm single crystal.