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Parallel Phosgenite Crystals
CARBONATES; · TETRAGONAL

Phosgenite

Pb2(CO)3Cl2

Hardness
2.5–3
Streak
White
Spec. Gravity
6.0–6.3
System
Tetragonal

About

Phosgenite is very rare, and good crystals are highly cherished among experienced mineral collectors, commanding very high prices. The large crystals that were found in Monteponi in Italy are true legendary classics. Phosgenite is a difficult mineral to obtain, with no significant discoveries in recent times.

Crystal Forms & Aggregates

Well-developed crystals are usually long and prismatic, but may also be short and tabular and in parallel growths. Crystals are striated lengthwise, and may have pointed terminations. Besides for a few minor exceptions, large crystals have only come from the Sardinian lead mines; all other forms are usually in very small crystals or in columnar and grainy aggregates. Phosgenite crystals are very recognizable.

Other ID Marks

Complex Tests

Striking Features

Environment

As a secondary lead mineral, often found at slag localities near sea water deposits.

Uses

Phosgenite is of interest to collectors because of its rarity and unique crystals, and is also highly sought after by collectors who specialize on fluorescent minerals.

Noteworthy Localities

The all-time classic locality for this mineral is the Monteponi Mine, Iglesias, on the Island of Sardinia, Italy. This locality has produced large crystals with excellent form.
Two African localities have also produced good specimens, namely the Touissit Mine in Morocco and the Tsumeb Mine in Tsumeb, Namibia. Small crystals have come from Matlock, Derbyshire, England; Tarnowitz, Poland; Dundas, Tasmania, and Broken Hill, New South Wales, Australia. Phosgenite also occurs as an alteration product of the lead slags at Lavrion Greece.

Phosgenite has been found only sparingly in the U.S., particularly at the Mammoth-Saint Anthony Mine, Tiger, Pinal Co., Arizona; the Terrible Mine in Custer Co., Colorado; the Stephenson-Bennet Mine in Dona Ana Co., New Mexico; and the Silver Sprout Mine in Inyo Co., California.

Common Mineral Associations

Distinguishing Similar Minerals

Photos

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Crystal forms

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Tetragonal Modified Pseudocube
Tetragonal Highly Modified Pseudocube
Tetragonal Rectangular
Modified Flattened Octagonal