World Library  
Flag as Inappropriate
Email this Article

Ball clay

Article Id: WHEBN0005801630
Reproduction Date:

Title: Ball clay  
Author: World Heritage Encyclopedia
Language: English
Subject: Pottery, Geology of Devon, Bovey Heath, Bovey Formation, Sea pottery
Collection: Clay, Geology of Devon, Pottery
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Ball clay

Ball clays are kaolinitic sedimentary clays that commonly consist of 20-80% kaolinite, 10-25% mica, 6-65% quartz. Localized seams in the same deposit have variations in composition, including the quantity of the major minerals, accessory minerals and carbonaceous materials such as lignite.[1] They are fine-grained and plastic in nature, and, unlike most earthenware clays, produce a fine quality white-coloured pottery body when fired, which is the key to their popularity with potters.

Ball clays are relatively scarce deposits due to the combination of geological factors needed for their formation and preservation. They are mined in parts of the Eastern United States and from three sites[2] in Devon and Dorset in South West England.[3] They are commonly used in the construction of many ceramic articles, where their primary role, apart from their white colour, is to either to impart plasticity or to aid rheological stability during the shaping processes.

Contents

  • History 1
  • See also 2
  • Notes 3
  • References 4

History

The name "ball clay" is believed to derive from the time when the clay was mined by hand. It was cut into 15 to 17-kilogram cubes and during transport the corners of the cubes became rounded off leaving "balls".[1]

The ceramic use of ball clays in Britain dates back to at least the Roman era. More recent trade began when a clay was needed to construct tobacco pipes in the 16th and 17th century.[4] In 1771 Josiah Wedgwood signed a contract for 1400 tons a year of ball clay with Thomas Hyde of Purbeck,[note 1] enabling him to fire thinner walled ceramics.[5]

See also

Notes

References

  1. ^ a b "What is ball clay?". Industrial Minerals Association - North America. Retrieved 2008-08-05. 
  2. ^ The Bovey Basin in South Devon, the Petrockstowe Basin in North Devon and the Wareham Basin in South Dorset.
  3. ^ Highley, David; Bloodworth, Andrew; Bate, Richard (2006). "Ball Clay - Mineral Planning Factsheet" (pdf file). British Geological Survey. Retrieved 2008-08-05. 
  4. ^ "The Widespread Use of Ball Clay". Introduction to Ball Clays. The Ball Clay Heritage Society. Retrieved 2008-08-05. 
  5. ^ "History of Ball Clay - Swanage Railway". The Purbeck Mineral & Mining Museum. Retrieved 2008-08-05. 
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.