Editing Clunch (section)

==Properties==
The stone is a chalk from the Lower Chalk of the [[Cretaceous]] age, the period of geological time approximately 145–66 million years ago.  It is greyish-white to light beige in colour, often with a greenish tinge. The latter is caused by the presence of glauconite, the potassium and iron aluminium silicate mineral that is also found in [[Kentish Ragstone]].<ref>{{cite web|url=http://projects.bre.co.uk/ConDiv/stonelist/camclunch.html |title=Cambridgeshire Clunch |publisher=Projects.bre.co.uk |date= |accessdate=2013-06-20}}</ref> The stone has a gritty texture because of the frequent presence of shell fossils. This stone has been quarried at Totternhoe Quarry in [[Dunstable]], [[Bedfordshire]], by H. G. Clarke & Son since 1920.<ref>{{cite web |url=http://clunch.co.uk |title=Clunch: traditional English chalk stone|publisher=H. G. Clarke and Son |archive-url=https://web.archive.org/web/20090606055550/http://www.clunch.co.uk/ |archive-date=6 June 2009 |url-status=dead}}</ref>

It is particularly soft when quarried and subject to chemical and wind [[erosion]] as exposed material, i.e. when [[Cement render|unrendered in paint, stucco or cement]]. It can be cut by a saw when in its softer state; when it has been quarried out of the ground it still contains a large amount of water.<ref>{{cite web|url=http://www.bbc.co.uk/threecounties/content/articles/2006/06/29/goneforclunch_feature.shtml |title=Gone for Clunch |publisher=BBC |date=2006-06-29 |accessdate=2013-06-20}}</ref> When the stone dries out it becomes harder, and is not as easy to cut.

Clunch is generically a soft [[limestone]]. It can be [[ironstone|rich in iron-bearing clays]] or be very fine and white &ndash; in effect just chalk. It is used in various parts of [[East Anglia]], where more durable stone is uncommon, and can be seen frequently in and around [[Thetford]] &ndash; mostly now for property boundary walls as it is not a long-lasting material, but it is also used for some building walls, especially in traditional [[agriculture|agricultural]] buildings.

In [[Ely Cathedral]] it can be seen in some interior locations. The nearby village of [[Burwell, Cambridgeshire|Burwell]] has its [[civil parishes in England|civil parish]] magazine named after the building material.<ref>{{cite web|url=http://www.burwell.co.uk/clunch/index.asp |title=Burwell Parish magazine |publisher=Burwell.co.uk |date= |accessdate=2013-06-20}}</ref> It is found in the village of [[Seale, Surrey|Seale]] in Surrey and in [[Farnham]].<ref>[http://www.guildford.gov.uk/NR/rdonlyres/6F4B8926-BFDF-485F-A933-FA38D2D8E56C/0/AdvisoryLeaflet9RepairandmaintenanceofStoneBuildingsPart1.pdf Guildford Borough Council Advisory Leaflet]{{dead link|date=June 2013}}</ref>