World Library  
Flag as Inappropriate
Email this Article

Cerussite

Article Id: WHEBN0000617624
Reproduction Date:

Title: Cerussite  
Author: World Heritage Encyclopedia
Language: English
Subject: WikiProject Rocks and minerals/Worklist, List of minerals C (complete), Mendipite, Adamantine Spar, Campylite
Collection: Carbonate Minerals, Lead Minerals, Orthorhombic Minerals
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Cerussite

Cerussite
Cerussite, Les Farges Mine – France
General
Category Carbonate mineral
Formula
(repeating unit)
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 cruise 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.

Finely crystallized specimens have been obtained from the 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.

Contents

  • Commercial uses 1
  • Cerussite Images 2
  • See also 3
  • References 4

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]

Cerussite Images

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
  5. ^ "Iconic: Light of the Desert". 2009-11-26. Retrieved 2012-07-25. 
  • Mineral galleries
  •  
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.