Cerussite


Cerussite
Cerussite

Cerussite, Les Frages Mine – France
General
Category Carbonate mineral
Chemical formula Lead carbonate: PbCO3
Strunz classification 05.AB.15
Identification
Color Colorless, white, gray, blue, or green
Crystal habit Massive granular, reticulate, tabular to equant crystals
Crystal system Orthorhombic – Dipyramidal (2/m 2/m 2/m)
Twinning Simple or cyclic contact twins
Cleavage Good [110] and [021]
Fracture Brittle conchoidal
Mohs scale hardness 3 to 3.5
Luster Adamantine, vitreous, resinous
Streak White
Diaphaneity Transparent to translucent
Specific gravity 6.53–6.57
Optical properties Biaxial (-)
Refractive index nα = 1.803, nβ = 2.074, nγ = 2.076
Birefringence δ = 0.273
Other characteristics May fluoresce yellow under LW UV
References [1][2]

Cerussite (also known as lead carbonate or white lead ore) 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 crystallizes 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 conchoidal 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.

As crystalline ore

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.

Commercial uses

"White lead" is the key ingredient in (now discontinued) lead paints. Ingestion of lead-based paint chips is the most common cause of lead poisoning in children.[3]

Both "white lead" and lead acetate have been used in cosmetics throughout history, though this practice has ceased in Western countries.[4]

Crystals of cerussite, a secondary lead ore

See also

References

  1. ^ Cerussite. Handbook of Mineralogy. (PDF) . Retrieved on 2011-10-10.
  2. ^ Cerussite. Mindat. Retrieved on 2011-10-10.
  3. ^ Lightening the Lead Load in Children as cited in Lead Poisoning in Children, and California Poison Control System: Lead Poisoning
  4. ^ Gunn, Fenja. (1973). The Artificial Face: A History of Cosmetics. — as cited in Leisure Activities of an 18th Century Lady and Reading Our Lips: The History of Lipstick Regulation in Western Seats of Power

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Look at other dictionaries:

  • cerussite — [sir′ə sīt΄, sə rus′īt΄] n. [< L cerussa (see CERUSE) + ITE1] a soft, heavy, orthorhombic mineral, PbCO3, that is an ore of lead; lead carbonate …   English World dictionary

  • Cerussite — Cérusite Cérusite CatégorieV : carbonates et nitrates Cérusite et malachite Tsumeb Namibie (7x5cm) Général …   Wikipédia en Français

  • Cerussite — Cerusite Ce ru*site, Cerussite Ce rus*site, n. (Min.) Native lead carbonate; a mineral occurring in colorless, white, or yellowish transparent crystals, with an adamantine, also massive and compact. [1913 Webster] …   The Collaborative International Dictionary of English

  • cerussite — cerusitas statusas T sritis chemija apibrėžtis Mineralas. formulė PbCO₃ atitikmenys: angl. cerussite rus. церуссит …   Chemijos terminų aiškinamasis žodynas

  • cerussite — noun Etymology: German Zerussit, from Latin cerussa Date: 1850 a colorless or white mineral consisting of a carbonate of lead that occurs in transparent crystals and also in massive form and is a source of white lead …   New Collegiate Dictionary

  • cerussite — /sear euh suyt , si rus uyt/, n. a mineral, lead carbonate, PbCO3, found in masses or in colorless, transparent crystals: an important ore of lead. [1840 50; < L ceruss(a) CERUSE + ITE1] * * * ▪ mineral  lead carbonate (PbCO3), an important ore… …   Universalium

  • cerussite — noun A mineral form of lead carbonate, PbCO, that is an ore of lead …   Wiktionary

  • cerussite —    A cave mineral PbCO3 [11] …   Lexicon of Cave and Karst Terminology

  • cerussite — ce·rus·sì·te s.f. TS mineral. carbonato di piombo grigiastro o incolore, rinvenuto sotto forma di cristalli nello strato superficiale dei giacimenti di galena {{line}} {{/line}} DATA: 1888 …   Dizionario italiano

  • cerussite — {{hw}}{{cerussite}}{{/hw}}s. f. Minerale, carbonato di piombo, da cui si estrae piombo …   Enciclopedia di italiano