{"id":40533,"date":"2024-04-03T12:08:19","date_gmt":"2024-04-03T04:08:19","guid":{"rendered":"https:\/\/honwaygroup.com\/why-is-gemstone-cleavage-important-for-design\/"},"modified":"2024-12-03T18:09:37","modified_gmt":"2024-12-03T10:09:37","slug":"why-is-gemstone-cleavage-important-for-design","status":"publish","type":"post","link":"https:\/\/honwaygroup.com\/en\/why-is-gemstone-cleavage-important-for-design\/","title":{"rendered":"Why is &#8220;cleavage&#8221; important in design?"},"content":{"rendered":"\n<div class=\"wp-block-rank-math-toc-block\" id=\"rank-math-toc\"><nav><ul><li class=\"\"><a href=\"#%E8%A7%A3%E7%90%86%E4%BB%8B%E7%B4%B9\"><a href=\"#%E8%A7%A3%E7%90%86%E4%BB%8B%E7%B4%B9\">Introduction to cleavage<\/a><\/a><\/li><li class=\"\"><a href=\"#%E4%BE%9D%E8%A7%A3%E7%90%86%E9%9D%A2%E7%9A%84%E5%AE%8C%E5%A5%BD%E7%A8%8B%E5%BA%A6%E8%A9%B3%E7%B4%B0%E5%8D%80%E5%88%86%E7%82%BA%E4%BA%94%E7%B4%9A\"><a href=\"#%E4%BE%9D%E8%A7%A3%E7%90%86%E9%9D%A2%E7%9A%84%E5%AE%8C%E5%A5%BD%E7%A8%8B%E5%BA%A6%E8%A9%B3%E7%B4%B0%E5%8D%80%E5%88%86%E7%82%BA%E4%BA%94%E7%B4%9A\">Cleavage plane grades<\/a><\/a><\/li><li class=\"\"><a href=\"#%E7%B8%BD%E7%B5%90\">Summary<\/a><\/li><\/ul><\/nav><\/div>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"\u89e3\u7406\u4ecb\u7d39\"><strong>Introduction<\/strong> to cleavage<\/h3>\n\n\n\n<p>Cleavage refers to the tendency of a crystallized mineral to break along planes of weakness within the crystal structure, forming smooth surfaces, under the influence of external force. The direction and ease of cleavage are controlled by the crystal structure. Since crystals are anisotropic, the bonding strength varies between different directions and planes. Generally, <strong>cleavage planes are parallel to the crystal faces<\/strong>. For example, if a gemstone has one set of cleavage, in the gemstone industry, this characteristic is utilized by striking along the cleavage plane to break it before cutting and polishing.<\/p>\n\n\n\n<p>For gemstone minerals, it is crucial to pay attention to the cleavage properties during design and polishing to avoid cracking easily upon impact.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large is-resized\"><a href=\"https:\/\/honwaygroup.com\/wp-content\/uploads\/2024\/04\/\u89e3\u88e1\u9762\u89e3\u91cb\u5716-02-1024x630.jpg\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"630\" src=\"https:\/\/honwaygroup.com\/wp-content\/uploads\/2024\/04\/\u89e3\u88e1\u9762\u89e3\u91cb\u5716-02-1024x630.jpg\" alt=\"Cleavage introduction diagram\" class=\"wp-image-62849\" style=\"width:923px;height:auto\" srcset=\"https:\/\/honwaygroup.com\/wp-content\/uploads\/2024\/04\/\u89e3\u88e1\u9762\u89e3\u91cb\u5716-02-1024x630.jpg 1024w, https:\/\/honwaygroup.com\/wp-content\/uploads\/2024\/04\/\u89e3\u88e1\u9762\u89e3\u91cb\u5716-02-300x184.jpg 300w, https:\/\/honwaygroup.com\/wp-content\/uploads\/2024\/04\/\u89e3\u88e1\u9762\u89e3\u91cb\u5716-02-768x472.jpg 768w, https:\/\/honwaygroup.com\/wp-content\/uploads\/2024\/04\/\u89e3\u88e1\u9762\u89e3\u91cb\u5716-02-1536x945.jpg 1536w, https:\/\/honwaygroup.com\/wp-content\/uploads\/2024\/04\/\u89e3\u88e1\u9762\u89e3\u91cb\u5716-02-2048x1259.jpg 2048w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption class=\"wp-element-caption\">Introduction to Cleavage<\/figcaption><\/figure>\n\n\n\n<h3 class=\"wp-block-heading has-medium-font-size\" id=\"\u4f9d\u89e3\u7406\u9762\u7684\u5b8c\u597d\u7a0b\u5ea6\u8a73\u7d30\u5340\u5206\u70ba\u4e94\u7d1a\"><strong>Detailed Classification of Cleavage Planes into Five Grades:<\/strong><\/h3>\n\n\n\n<figure class=\"wp-block-table is-style-regular\"><table><tbody><tr><td class=\"has-text-align-center\" data-align=\"center\"><strong>Cleavage grades<\/strong><\/td><td class=\"has-text-align-left\" data-align=\"left\"><strong>Ease of Cleavage<\/strong><\/td><td><strong>Mineral<\/strong><\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Perfect Cleavage<\/td><td class=\"has-text-align-left\" data-align=\"left\">The mineral easily splits into thin sheets, forming large, smooth, and flat cleavage planes.<\/td><td>e.g. mica and gypsum<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Good Cleavage<\/td><td class=\"has-text-align-left\" data-align=\"left\">A light hammer strike will cause the mineral to split along the cleavage plane into small pieces, with fairly smooth cleavage planes.<\/td><td>e.g. <a href=\"https:\/\/honwaygroup.com\/en\/advanced-refractory-materials-kyanite\/\" target=\"_blank\" rel=\"noreferrer noopener\">kyanite<\/a>, <a href=\"https:\/\/honwaygroup.com\/en\/a-gemstone-that-glows-at-night-fluorite-fluorite\/\" target=\"_blank\" rel=\"noreferrer noopener\">fluorite<\/a>, calcite, feldspar<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Fair Cleavage<\/td><td class=\"has-text-align-left\" data-align=\"left\">The cleavage plane often does not break completely through, is not very smooth, and is discontinuous.<\/td><td>e.g. chrysoberyl, <a href=\"https:\/\/honwaygroup.com\/en\/a-gemstone-that-radiates-moonlight-like-sheen-moonstone\/\" target=\"_blank\" rel=\"noreferrer noopener\">orthoclase<\/a><\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Poor Cleavage<\/td><td class=\"has-text-align-left\" data-align=\"left\">Cleavage planes are difficult to observe, and most fractures are irregular.<\/td><td>e.g. olivine and <a href=\"https:\/\/honwaygroup.com\/en\/the-deceptive-gemstone-apatite\/\" target=\"_blank\" rel=\"noreferrer noopener\">apatite<\/a><\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">No Cleavage<\/td><td class=\"has-text-align-left\" data-align=\"left\">No cleavage<\/td><td>e.g. ruby, sapphire, tourmaline, zircon, and garnet<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p><strong>Number of cleavage planes<\/strong>: If a mineral has multiple parallel cleavage planes, it is said to have one set of cleavage planes. Cleavage planes usually correspond to weak planes within the mineral crystal. If a mineral has multiple weak planes in different directions, it will exhibit multiple sets of cleavage planes. <\/p>\n\n\n\n<p><strong>Cleavage angle<\/strong>: If a mineral has two sets of cleavage planes, the angle between them is known as the cleavage angle, which is the angle between specific crystal faces within the crystal. Cleavage angles can generally be categorized into right angles, acute angles, and obtuse angles. The cleavage angle can be an important indicator in the identification of certain minerals.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-ast-global-color-0-color has-text-color has-link-color wp-elements-5a897e496a36f32a0b3b0a6414d534ec\" id=\"\u7e3d\u7d50\"><strong>Summary<\/strong><\/h3>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-link-color wp-elements-3512f3fa69cf74973fe0624c591429af\">Each gemstone crystal system has a different structural arrangement, resulting in varying numbers and angles of cleavage planes. For instance, mica has one set of perfect cleavage, while calcite has three sets of perfect cleavage. The morphology of minerals is often related to cleavage, as seen in mica, which can be split into thin layers, and Iceland spar, which fractures into rhombohedra. These characteristics can be used to differentiate between minerals.<\/p>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-link-color wp-elements-623d83cb6a4421743eee4d658b593749\">Cleavage is an inherent property of gemstones, and its presence depends on the symmetry of the gemstone. Even perfectly crystallized diamonds, though free from fractures, still have cleavage planes. When designing and polishing gemstones, it is important to pay special attention to their cleavage properties to avoid cracks from slight impacts.<\/p>\n\n\n\n<figure class=\"wp-block-pullquote has-medium-font-size\"><blockquote><p>Follow Honway to learn more about gemstones~<\/p><\/blockquote><\/figure>\n\n\n\n<p><\/p>\n\n\n\n<p>Citation<\/p>\n\n\n\n<p><a href=\"http:\/\/digimuse.nmns.edu.tw\/Default.aspx?ObjectId=0b00000181c8de88&amp;Domin=g&amp;tabid=193&amp;Field=m0&amp;ContentType=Exhibit&amp;FieldName=&amp;Language=CHI\" target=\"_blank\" rel=\"noreferrer noopener nofollow\"><\/a><a href=\"http:\/\/digimuse.nmns.edu.tw\/Default.aspx?ObjectId=0b00000181c8de88&amp;Domin=g&amp;tabid=193&amp;Field=m0&amp;ContentType=Exhibit&amp;FieldName=&amp;Language=CHI\" rel=\"nofollow noopener\" target=\"_blank\">National Digital Archives Program\/National Museum of Natural Science<\/a><\/p>\n\n\n\n<p><a href=\"https:\/\/www.earthsciences.hku.hk\/shmuseum\/chi\/earth_mat_1_2_5.php\" target=\"_blank\" rel=\"noreferrer noopener nofollow\"><\/a><a href=\"https:\/\/www.earthsciences.hku.hk\/shmuseum\/chi\/earth_mat_1_2_5.php\" rel=\"nofollow noopener\" target=\"_blank\">Stephen Hui Geological Museum<\/a><\/p>\n\n\n\n<p>It turns out that gemstones also have OCD: even when they break, they do so in a smooth, flat, and grand manner. Original text URL: <a href=\"https:\/\/kknews.cc\/collect\/66xly63.html\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">https:\/\/kknews.cc\/collect\/66xly63.html<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Cleavage refers to the property where a crystallized mineral breaks along weaker planes within the crystal structure under external force, forming smooth surfaces. In the gemstone industry, the cleavage characteristic is utilized by striking along the cleavage plane before cutting and polishing. Cleavage is classified into five grades based on the degree of perfection: perfect cleavage, good cleavage, fair cleavage, poor cleavage, and no cleavage. Cleavage is not only a critical factor in gemstone design but also serves as an important indicator in gemstone identification. Cleavage is an inherent property of gemstones, and even perfectly crystallized diamonds have cleavage planes.<\/p>\n","protected":false},"author":1,"featured_media":62849,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[795],"tags":[2309],"class_list":["post-40533","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-science-classroom","tag-cleavage"],"_links":{"self":[{"href":"https:\/\/honwaygroup.com\/en\/wp-json\/wp\/v2\/posts\/40533","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/honwaygroup.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/honwaygroup.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/honwaygroup.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/honwaygroup.com\/en\/wp-json\/wp\/v2\/comments?post=40533"}],"version-history":[{"count":0,"href":"https:\/\/honwaygroup.com\/en\/wp-json\/wp\/v2\/posts\/40533\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/honwaygroup.com\/en\/wp-json\/wp\/v2\/media\/62849"}],"wp:attachment":[{"href":"https:\/\/honwaygroup.com\/en\/wp-json\/wp\/v2\/media?parent=40533"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/honwaygroup.com\/en\/wp-json\/wp\/v2\/categories?post=40533"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/honwaygroup.com\/en\/wp-json\/wp\/v2\/tags?post=40533"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}