Cerussite
Encyclopedia
Cerussite is a mineral
consisting of lead
carbonate
(PbCO3), and an important ore
of lead. The name is from the Latin
cerussa, white lead. Cerussa nativa was mentioned by Conrad Gessner
in 1565, and in 1832 F. S. Beudant
applied the name cruse to the mineral, whilst the present form, cerussite, is due to W. Haidinger (1845). Miners' names in early use were lead-spar and white-lead-ore.
Cerussite crystal
lizes in the orthorhombic system and is isomorphous with aragonite
. Like aragonite it is very frequently twinned
, the compound crystals being pseudo-hexagonal in form. Three crystals are usually twinned together on two faces of the prism, producing six-rayed stellate groups with the individual crystals intercrossing at angles of nearly 60°. Crystals are of frequent occurrence and they usually have very bright and smooth faces. The mineral also occurs in compact granular masses, and sometimes in fibrous forms. The mineral is usually colorless or white, sometimes grey or greenish in tint and varies from transparent to translucent with an adamantine lustre. It is very brittle, and has a conchoid
al fracture. It has a Mohs hardness of 3 to 3.75 and a specific gravity
of 6.5. A variety containing 7% of zinc carbonate, replacing lead carbonate, is known as iglesiasite, from Iglesias in Sardinia
, where it is found.
The mineral may be readily recognized by its characteristic twinning, in conjunction with the adamantine lustre and high specific gravity. It dissolves with effervescence in dilute nitric acid
. A blowpipe test will cause it to fuse very readily, and gives indications for lead.
Finely crystallized specimens have been obtained from the Friedrichssegen mine in Lahnstein
near Nassau
, Johanngeorgenstadt
in Saxony
, Mies
in Bohemia
, Phoenixville in Pennsylvania
, Broken Hill, New South Wales
; and several other localities. Delicate acicular crystals of considerable length were found long ago in the Pentire Glaze mine near St Minver
in Cornwall
. It is often found in considerable quantities, and contains as much as 77.5% of lead.
Lead(II) carbonate is practically insoluble in neutral water (solubility product [Pb2+][CO32–] ≈ 1.5×10–13 at 25 °C), but will dissolve in dilute acids.
" is the key ingredient in (now discontinued) lead paint
s. Ingestion of lead-based paint chips is the most common cause of lead poisoning
in children.
Both "white lead" and lead acetate
have been used in cosmetics throughout history, though this practice has ceased in Western countries.
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...
carbonate
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....
(PbCO3), and an important ore
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
of lead. The name is from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
cerussa, white lead. Cerussa nativa was mentioned by Conrad Gessner
Conrad Gessner
Conrad Gessner was a Swiss naturalist and bibliographer. His five-volume Historiae animalium is considered the beginning of modern zoology, and the flowering plant genus Gesneria is named after him...
in 1565, and in 1832 F. S. Beudant
François Sulpice Beudant
François Sulpice Beudant , French mineralogist and geologist, was born in Paris.He was educated at the Ecole Polytechnique and Ecole Normale, and in 1811 was appointed professor of mathematics at the lycée of Avignon. Thence he was called, in 1813, to the lycée of Marseilles to fill the post of...
applied the name cruse to the mineral, whilst the present form, cerussite, is due to W. Haidinger (1845). Miners' names in early use were lead-spar and white-lead-ore.
Cerussite 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...
lizes in the orthorhombic system and is isomorphous with aragonite
Aragonite
Aragonite is a carbonate mineral, one of the two common, naturally occurring, crystal forms of calcium carbonate, CaCO3...
. Like aragonite it is very frequently twinned
Crystal twinning
Crystal twinning occurs when two separate crystals share some of the same crystal lattice points in a symmetrical manner. The result is an intergrowth of two separate crystals in a variety of specific configurations. A twin boundary or composition surface separates the two crystals....
, the compound crystals being pseudo-hexagonal in form. Three crystals are usually twinned together on two faces of the prism, producing six-rayed stellate groups with the individual crystals intercrossing at angles of nearly 60°. Crystals are of frequent occurrence and they usually have very bright and smooth faces. The mineral also occurs in compact granular masses, and sometimes in fibrous forms. The mineral is usually colorless or white, sometimes grey or greenish in tint and varies from transparent to translucent with an adamantine lustre. It is very brittle, and has a conchoid
Conchoid
Conchoid can refer to:*Conchoid curve, an equation discovered by the mathematician Nicomedes*Conchoidal fracture, a breakage pattern characteristic to certain glasses and crystals...
al fracture. It has a Mohs hardness of 3 to 3.75 and a 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...
of 6.5. A variety containing 7% of zinc carbonate, replacing lead carbonate, is known as iglesiasite, from 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[],...
, where it is found.
The mineral may be readily recognized by its characteristic twinning, in conjunction with the adamantine lustre and high specific gravity. It dissolves with effervescence in dilute nitric acid
Nitric acid
Nitric acid , also known as aqua fortis and spirit of nitre, is a highly corrosive and toxic strong acid.Colorless when pure, older samples tend to acquire a yellow cast due to the accumulation of oxides of nitrogen. If the solution contains more than 86% nitric acid, it is referred to as fuming...
. A blowpipe test will cause it to fuse very readily, and gives indications for lead.
Lahnstein
Lahnstein is a verband-free town of Rhein-Lahn-Kreis in Rhineland-Palatinate, Germany. It is situated at the confluence of the Lahn River with the Rhine, approximately south of Koblenz...
near Nassau
Nassau, Germany
Nassau is a town located in the German Land of Rhineland-Palatinate. It lies in the Lahn River valley between the cities of Bad Ems and Limburg an der Lahn. Nassau is the seat of the Verbandsgemeinde of Nassau. The town is on the German-Dutch holiday road, the Orange Route...
, Johanngeorgenstadt
Johanngeorgenstadt
Johanngeorgenstadt is a mining town in Saxony’s Ore Mountains, 17 km south of Aue, and 27 km northwest of Karlovy Vary. It lies in the district of Erzgebirgskreis, and right on the border with the Czech Republic, is a state-recognized health resort , and calls itself Stadt des...
in Saxony
Saxony
The Free State of Saxony is a landlocked state of Germany, contingent with Brandenburg, Saxony Anhalt, Thuringia, Bavaria, the Czech Republic and Poland. It is the tenth-largest German state in area, with of Germany's sixteen states....
, Mies
Mies
Mies is a municipality in the district of Nyon in the canton of Vaud in Switzerland.It is approximately half-way between Geneva and Nyon. Mies sits on Lake Geneva , which lies to the southeast and is 410m above sea-level. The highest point of Mies is 455m above sea level. The part of Mies touching...
in Bohemia
Bohemia
Bohemia is a historical region in central Europe, occupying the western two-thirds of the traditional Czech Lands. It is located in the contemporary Czech Republic with its capital in Prague...
, Phoenixville in Pennsylvania
Pennsylvania
The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...
, Broken Hill, New South Wales
Broken Hill, New South Wales
-Geology:Broken Hill's massive orebody, which formed about 1,800 million years ago, has proved to be among the world's largest silver-lead-zinc mineral deposits. The orebody is shaped like a boomerang plunging into the earth at its ends and outcropping in the centre. The protruding tip of the...
; and several other localities. Delicate acicular crystals of considerable length were found long ago in the Pentire Glaze mine near St Minver
St Minver
St Minver is the name of an ecclesiastical parish, a civil parish and a village in north Cornwall, United Kingdom.The civil parish of St Minver is in Bodmin Registration District and is nominally divided into St Minver Highlands and St Minver Lowlands .The combined parish is bounded on the south...
in Cornwall
Cornwall
Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...
. It is often found in considerable quantities, and contains as much as 77.5% of lead.
Lead(II) carbonate is practically insoluble in neutral water (solubility product [Pb2+][CO32–] ≈ 1.5×10–13 at 25 °C), but will dissolve in dilute acids.
Commercial uses
"White leadWhite lead
White lead is the chemical compound 2·Pb2. It was formerly used as an ingredient for lead paint and a cosmetic called Venetian Ceruse, because its opaque quality made it a good pigment. However, it tended to cause lead poisoning, and its use has been banned in most countries.White lead has been...
" is the key ingredient in (now discontinued) lead paint
Lead paint
Lead paint or lead-based paint is paint containing lead, a heavy metal, that is used as pigment, with lead chromate and lead carbonate being the most common. Lead is also added to paint to speed drying, increase durability, retain a fresh appearance, and resist moisture that causes corrosion...
s. Ingestion of lead-based paint chips is the most common cause of lead poisoning
Lead poisoning
Lead poisoning is a medical condition caused by increased levels of the heavy metal lead in the body. Lead interferes with a variety of body processes and is toxic to many organs and tissues including the heart, bones, intestines, kidneys, and reproductive and nervous systems...
in children.
Both "white lead" and lead acetate
Lead acetate
Lead acetate can refer to:* Lead acetate , Pb4* Lead acetate , Pb2...
have been used in cosmetics throughout history, though this practice has ceased in Western countries.