{"id":2220,"date":"2025-11-27T12:05:58","date_gmt":"2025-11-27T17:05:58","guid":{"rendered":"https:\/\/iversonsoftware.com\/wp\/?p=2220"},"modified":"2025-11-27T12:05:58","modified_gmt":"2025-11-27T17:05:58","slug":"afwillite","status":"publish","type":"post","link":"https:\/\/iversonsoftware.com\/wp\/afwillite\/","title":{"rendered":"Afwillite"},"content":{"rendered":"<p><!--StartFragment --><\/p>\n<p><strong>Afwillite is a rare calcium silicate hydrate mineral, typically found in metamorphosed limestones and sometimes in cement chemistry contexts.<\/strong> It is scientifically important for understanding hydration processes in silicates and low-temperature metamorphism.<\/p>\n<hr \/>\n<h2>\ud83c\udf0d Origins and Naming<\/h2>\n<ul>\n<li><strong>First Described:<\/strong> 1925<\/li>\n<li><strong>Name Origin:<\/strong> Named after <strong>Alpheus Fuller Williams (1874\u20131953)<\/strong>, General Manager of De Beers Consolidated Mines in Kimberley, South Africa.<\/li>\n<li><strong>Type Locality:<\/strong> Dutoitspan diamond mine, Kimberley, and Wessels mine near Kuruman, Cape Province, South Africa.<\/li>\n<\/ul>\n<hr \/>\n<h2>\ud83d\udd2c Chemical and Structural Properties<\/h2>\n<ul>\n<li><strong>Formula:<\/strong> Ca\u2083(SiO\u2083OH)\u2082\u00b72H\u2082O<\/li>\n<li><strong>Mineral Group:<\/strong> Nesosilicates<\/li>\n<li><strong>Crystal System:<\/strong> Monoclinic<\/li>\n<li><strong>Color:<\/strong> Colorless to white<\/li>\n<li><strong>Habit:<\/strong> Prismatic, tabular, radial fibrous, or massive crystals<\/li>\n<li><strong>Hardness:<\/strong> 3\u20134 on Mohs scale<\/li>\n<li><strong>Specific Gravity:<\/strong> ~2.63<\/li>\n<li><strong>Luster:<\/strong> Vitreous<\/li>\n<li><strong>Streak:<\/strong> White<\/li>\n<li><strong>Optical Properties:<\/strong> Biaxial (+), refractive indices n\u03b1 = 1.617, n\u03b2 = 1.620, n\u03b3 = 1.634<\/li>\n<li><strong>Other:<\/strong> Piezoelectric properties have been observed.<\/li>\n<\/ul>\n<hr \/>\n<h2>\u2699\ufe0f Geological Occurrence<\/h2>\n<p>Afwillite forms in:<\/p>\n<ul>\n<li><strong>Contact metamorphism of limestones<\/strong> (skarn environments)<\/li>\n<li><strong>Hydrothermal settings<\/strong> where calcium-rich fluids interact with silicates<\/li>\n<li><strong>Cement chemistry:<\/strong> It can appear in hydrated Portland cement phases, making it relevant to construction material science<\/li>\n<\/ul>\n<hr \/>\n<h2>\ud83d\udccd Notable Localities<\/h2>\n<ul>\n<li><strong>South Africa:<\/strong> Kimberley diamond mines (type locality)<\/li>\n<li><strong>California, USA:<\/strong> Crestmore Quarry, Riverside County<\/li>\n<li><strong>Other skarn deposits worldwide<\/strong> where calcium silicate hydrates occur.<\/li>\n<\/ul>\n<hr \/>\n<h2>\ud83d\udcd6 Scientific and Collector Significance<\/h2>\n<ul>\n<li><strong>Petrology:<\/strong> Important for understanding <strong>low- to moderate-temperature silicate hydration<\/strong> and stability.<\/li>\n<li><strong>Materials Science:<\/strong> Studied in relation to <strong>cement hydration and degradation processes<\/strong>, linking mineralogy with engineering applications.<\/li>\n<li><strong>Collectors:<\/strong> Rare and delicate crystals, not common in large specimens, but valued for their unusual fibrous or bladed habits.<\/li>\n<\/ul>\n<hr \/>\n<h2>\u2728 Conclusion<\/h2>\n<p>Afwillite is a <strong>calcium hydroxide nesosilicate mineral<\/strong> with a distinctive role in both geology and materials science. Though rare and not a mainstream collector\u2019s mineral, it is scientifically significant for its occurrence in metamorphosed limestones and its relevance to cement chemistry.<\/p>\n<hr \/>\n<p><strong>In short: Afwillite is a rare calcium silicate hydrate mineral, first described in South Africa, important in both geology and cement science.<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><!--EndFragment --><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Afwillite is a rare calcium silicate hydrate mineral, typically found in metamorphosed limestones and sometimes in cement chemistry contexts. It is scientifically important for understanding hydration processes in silicates and low-temperature metamorphism. \ud83c\udf0d Origins and Naming First Described: 1925 Name Origin: Named after Alpheus Fuller Williams (1874\u20131953), General Manager of De Beers Consolidated Mines in &hellip; <a href=\"https:\/\/iversonsoftware.com\/wp\/afwillite\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Afwillite&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-2220","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/iversonsoftware.com\/wp\/wp-json\/wp\/v2\/posts\/2220","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/iversonsoftware.com\/wp\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/iversonsoftware.com\/wp\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/iversonsoftware.com\/wp\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/iversonsoftware.com\/wp\/wp-json\/wp\/v2\/comments?post=2220"}],"version-history":[{"count":1,"href":"https:\/\/iversonsoftware.com\/wp\/wp-json\/wp\/v2\/posts\/2220\/revisions"}],"predecessor-version":[{"id":2221,"href":"https:\/\/iversonsoftware.com\/wp\/wp-json\/wp\/v2\/posts\/2220\/revisions\/2221"}],"wp:attachment":[{"href":"https:\/\/iversonsoftware.com\/wp\/wp-json\/wp\/v2\/media?parent=2220"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/iversonsoftware.com\/wp\/wp-json\/wp\/v2\/categories?post=2220"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/iversonsoftware.com\/wp\/wp-json\/wp\/v2\/tags?post=2220"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}