Conchoidal fracture

<h2 id="subsets">Subsets</h2>
<p>Several subdefinitions exist, for instance on the Webmineral website:<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a>
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<ul><li>Brittle—conchoidal: very brittle fracture producing small, conchoidal fragments</li>
<li>Brittle—subconchoidal: brittle fracture with subconchoidal fragments</li>
<li>Conchoidal—irregular: irregular fracture producing small, conchoidal fragments</li>
<li>Conchoidal—uneven: uneven fracture producing small, conchoidal fragments</li>
<li>Subconchoidal: fractures developed in brittle materials characterized by semi-curving surfaces</li></ul>
<h2 id="lithics">Lithics</h2>
<p>In <a href="/facts/Lithic_flake/4RLPRpX2">lithic</a> <a href="/facts/Stone_tool/JQxItKEm">stone tools</a>, conchoidal fractures form the basis of flint <a href="/facts/Knapping/FPPEFBvs">knapping</a>, since the shape of the broken surface is controlled only by the <a href="/facts/Stress_(physics)/ErAXDbbd">stresses</a> applied, and not by some preferred orientation of the material. This property also makes such fractures useful in engineering, since they provide a permanent record of the stress state at the time of <a href="/facts/Failure/hhLBhlhN">failure</a>. As conchoidal fractures can be produced only by mechanical impact, rather than <a href="/facts/Frost/0zan2Azj">frost</a> cracking for example, they can be a useful method of differentiating <a href="/facts/Stone_Age/r1KMneWW">prehistoric</a> stone tools from natural stones.
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<h2 id="see-also">See also</h2>
<ul>
<li>Geology portal</li></ul>
<ul><li><a href="/facts/Fracture_(mineralogy)/Xzc4yDjy">Fracture (mineralogy)</a></li></ul>

<h2 id="external-links">External links</h2>

Wikimedia Commons has media related to Conchoidal fracture.

<ul><li> The dictionary definition of conchoid at Wiktionary</li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>Conchoidal fracture at Mindat.org <a href="https://www.mindat.org/glossary/conchoidal_fracture" target="_blank">https://www.mindat.org/glossary/conchoidal_fracture</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>"Conchoidal". Merriam-Webster Online. Retrieved 2010-10-30. <a href="https://www.merriam-webster.com/dictionary/conchoidal" target="_blank">https://www.merriam-webster.com/dictionary/conchoidal</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>κογχοειδής, κόγχη. Liddell, Henry George; Scott, Robert; A Greek–English Lexicon at the Perseus Project. <a href="https://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry=kogxoeidh/s" target="_blank">https://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry=kogxoeidh/s</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>Mineral Tenacity and Fracture at Webmineral <a href="http://webmineral.com/help/Fracture.shtml" target="_blank">http://webmineral.com/help/Fracture.shtml</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
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Conchoidal fracture open-in-new

Conchoidal fracture