Difference between pages "Ball clay" and "Ballas"

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[[File:Ball clay.jpg|thumb|Ball Clay]]
 
 
== Description ==
 
== Description ==
  
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A fine, soft, very plastic clay. Ball clay is a relatively pure, [[secondary clay]] composed of [[kaolin]] (20-90%), [[mica]] (5-45%), and [[quartz]] (1-70%). The high quality clay is found in England (Wareham, Dorset, Devon) and the U.S. (Kentucky, Tennessee). Originally, ball clay was dug up and made into 30-35 pound balls for transportation by horses. The fine-grain clay contains small amounts of carbon and other organic materials that give it an initial dark color. These materials are combusted during firing leaving a white vessel. Ball clay is very plastic and has a high shrinkage rate of up to 20 %. It is often mixed with other clays to increase their plasticity. Ball clay is used in the manufacture of ceramics, whiteware, porcelain, glass, and tiles.
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Small, imperfectly crystallized pieces of [[diamond]]. Ballas stones are rounded with no distinct cleavage. They are extremely hard and tough. Ballas is mined in Brazil and South Africa. The industrial grade diamond is primarily used as an abrasive.
  
 
== Synonyms and Related Terms ==
 
== Synonyms and Related Terms ==
  
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argile plastique (Fr.); argila gorda (Port.)
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shot bort; industrial grade diamond
  
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==Resources and Citations==
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{| class="wikitable"
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|-
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! scope="row"| Composition
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| C
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|-
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! scope="row"| Mohs Hardness
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| 10
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|}
  
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* G.S.Brady, ''Materials Handbook'', McGraw-Hill Book Co., New York, 1971  Comment: p. 428
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== Comparisons ==
  
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* Ralph Mayer, ''A Dictionary of Art Terms and Techniques'', Harper and Row Publishers, New York, 1969 (also 1945 printing)
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[[media:download_file_183.pdf|Properties of Common Abrasives]]
  
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* Richard S. Lewis, ''Hawley's Condensed Chemical Dictionary'', Van Nostrand Reinhold, New York, 10th ed., 1993
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==Resources and Citations==
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* Henry Hodges, ''Artifacts: An Introduction to Early Materials and Technology'', Ronald P. Frye, Kingston, Canada, 1988
 
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* Robert Fournier, ''Illustrated Dictionary of Practical Pottery'', Chilton Book Company, Radnor, PA, 1992
 
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* Random House, ''Webster's Encyclopedic Unabridged Dictionary of the English Language'', Grammercy Book, New York, 1997
 
  
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* ''The Dictionary of Art'', Grove's Dictionaries Inc., New York, 1996  Comment: "Ceramics"
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* ''Van Nostrand's Scientific Encyclopedia'', Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
  
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* Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000
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* ''Encyclopedia Britannica'', https://www.britannica.com/topic/Britannica-Online  Comment: "industrial diamond"  [Accessed March 4, 2002].
  
  
  
 
[[Category:Materials database]]
 
[[Category:Materials database]]

Revision as of 16:46, 1 May 2022

Description

Small, imperfectly crystallized pieces of Diamond. Ballas stones are rounded with no distinct cleavage. They are extremely hard and tough. Ballas is mined in Brazil and South Africa. The industrial grade diamond is primarily used as an abrasive.

Synonyms and Related Terms

shot bort; industrial grade diamond

Composition C
Mohs Hardness 10

Comparisons

Properties of Common Abrasives

Resources and Citations

  • Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976

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