Phosgenite is a rare mineral

Mineral

A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...

 consisting of lead

Lead

Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...

 chlorocarbonate, (PbCl)₂CO₃. The tetragonal crystal

Crystal

A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...

s are prismatic

Prism (geometry)

In geometry, a prism is a polyhedron with an n-sided polygonal base, a translated copy , and n other faces joining corresponding sides of the two bases. All cross-sections parallel to the base faces are the same. Prisms are named for their base, so a prism with a pentagonal base is called a...

 or tabular in habit: they are usually colorless and transparent, and have a brilliant adamantine lustre

Lustre (mineralogy)

Lustre is a description of the way light interacts with the surface of a crystal, rock, or mineral. The word lustre traces its origins back to the Latin word lux, meaning "light", and generally implies radiance, gloss, or brilliance....

. Sometimes the crystals have a curious helical twist about the tetrad or principal axis. The hardness

Mohs scale of mineral hardness

The Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material. It was created in 1812 by the German geologist and mineralogist Friedrich Mohs and is one of several definitions of hardness in...

 is 3 and the specific gravity

Specific gravity

Specific gravity is the ratio of the density of a substance to the density of a reference substance. Apparent specific gravity is the ratio of the weight of a volume of the substance to the weight of an equal volume of the reference substance. The reference substance is nearly always water for...

 6.3. The mineral is rather sectile, and consequently was earlier known as corneous lead.

Name and occurrence

The name phosgenite was given by August Breithaupt

August Breithaupt

Johann Friedrich August Breithaupt was a German mineralogist and professor at Freiberg Mining Academy in Freiberg, Saxony.-Biography:...

 in 1820, from phosgene

Phosgene

Phosgene is the chemical compound with the formula COCl2. This colorless gas gained infamy as a chemical weapon during World War I. It is also a valued industrial reagent and building block in synthesis of pharmaceuticals and other organic compounds. In low concentrations, its odor resembles...

, carbon oxychloride, because the mineral contains the elements carbon

Carbon

Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...

, oxygen

Oxygen

Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

 and chlorine

Chlorine

Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...

.

It was found associated with anglesite

Anglesite

Anglesite is a lead sulfate mineral with the chemical formula PbSO4. It occurs as an oxidation product of primary lead sulfide ore, galena. Anglesite occurs as prismatic orthorhombic crystals and earthy masses, and is isomorphous with barite and celestine. It contains 74% of lead by mass and...

 and matlockite

Matlockite

Matlockite is a rare lead halide mineral, named after the town of Matlock in Derbyshire, England, where it was first discovered in a nearby mine...

 in cavities within altered galena

Galena

Galena is the natural mineral form of lead sulfide. It is the most important lead ore mineral.Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms...

 in a lead mine at Cromford

Cromford

Cromford is a village, two miles to the south of Matlock in the Derbyshire Dales district in Derbyshire, England. It is principally known for its historical connection with Richard Arkwright, and the Cromford Mill which he built here in 1771...

, near Matlock: hence its common name cromfordite. Crystals are also found in galena at Monteponi near Iglesias

Iglesias

Iglesias is a comune of Carbonia-Iglesias province in Sardinia, Italy.-Overview:Situated at 190 m in the hills in the southwest of Sardinia, it was a centre of a mining district, with lead, zinc, and silver being extracted, as well as for the distillation of sulfuric acid.Iglesias'...

 in Sardinia

Sardinia

Sardinia is the second-largest island in the Mediterranean Sea . It is an autonomous region of Italy, and the nearest land masses are the French island of Corsica, the Italian Peninsula, Sicily, Tunisia and the Spanish Balearic Islands.The name Sardinia is from the pre-Roman noun *sard[],...

, and near Dundas

Dundas

Dundas may refer to:Places* Dundas, Greenland* Dundas, Minnesota, United States* Dundas, New Brunswick, Canada* Dundas, New South Wales, Australia* Dundas, Ontario, Canada* Dundas, Tasmania, Australia* Dundas, Wisconsin, United States...

 in Tasmania

Tasmania

Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...

. It has also been reported from Laurium

Laurium

Laurium or Lavrio is a town in southeastern part of Attica, Greece. It is the seat of the municipality of Lavreotiki...

, Greece; Tarnowitz, Poland; the Altai district, Siberia

Siberia

Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...

; the Touissit mine, near Oujda

Oujda

Oujda is a city in eastern Morocco with an estimated population of 1 million. The city is located about 15 kilometers west of Algeria and about 60 kilometers south of the Mediterranean Sea. It is the capital of the Oriental Region of Morocco and the birthplace of the current Algerian president,...

, Morocco; Sidi Amor ben Salem, Tunisia; Tsumeb

Tsumeb

Tsumeb is a city of 15,000 inhabitants and the largest town in Oshikoto region in northern Namibia. Tsumeb is the home of the world-famous Tsumeb mine, and the "gateway to the north" of Namibia. It is the closest town to the Etosha National Park...

, Namibia; Broken Hill, New South Wales

New South Wales

New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...

; and Boleo, near Santa Rosalia

Santa Rosalia

Saint Rosalia , also called La Santuzza or "The Little Saint", is the patron saint of Palermo, Italy, El Hatillo, Venezuela, and Zuata, Anzoátegui, Venezuela.-Legend:...

, Baja California

Baja California

Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...

. In the US it has been reported from the Terrible mine, Custer County, Colorado

Custer County, Colorado

Custer County is the tenth least populous of the 64 counties of the State of Colorado of the United States. The county population was 3,503 at U.S. Census 2000. The county seat is Westcliffe.- History :...

; the Stevenson-Bennett mine, Organ Mountains

Organ Mountains

The Organ Mountains are a rugged mountain range in southern New Mexico in the Southwestern United States. They lie east of the city of Las Cruces, in Doña Ana County.-Geography:...

, Dona Ana County, New Mexico

Doña Ana County, New Mexico

-2010:Whereas according to the 2010 U.S. Census Bureau:*74.1% White*1.7% Black*1.5% Native American*1.1% Asian*0.1% Native Hawaiian or Pacific Islander*3.0% Two or more races*18.5% Other races*65.7% Hispanic or Latino -2000:...

; and the Mammoth mine, Tiger

Tiger, Arizona

Tiger is a ghost town in Pinal County in the U.S. state of Arizona. The town was settled as Schultz around 1881 in what was then the Arizona Territory, then later reestablished as Tiger after World War I.-History:...

, Pinal County, Arizona

Pinal County, Arizona

-2010:Whereas according to the 2010 U.S. Census Bureau:*72.4% White*4.6% Black*5.6% Native American*1.7% Asian*0.4% Native Hawaiian or Pacific Islander*3.8% Two or more races*11.5% Other races*28.5% Hispanic or Latino -2000:...

.

Crystals of phosgenite, and also of the corresponding bromine compound PbBr₂CO₃, have been prepared artificially.