{"title":"Tenebrescent Minerals","description":"\u003ch2 data-section-id=\"1neli12\" data-start=\"371\" data-end=\"395\" class=\"PDq2pG_selectionAnchorContainer\"\u003eTenebrescent Minerals\u003cspan aria-hidden=\"true\" class=\"PDq2pG_selectionAnchor\"\u003e\u003c\/span\u003e\n\u003c\/h2\u003e\n\u003cp data-start=\"397\" data-end=\"851\"\u003eExplore our collection of \u003cstrong data-start=\"423\" data-end=\"448\"\u003eTenebrescent Minerals\u003c\/strong\u003e, featuring mineral specimens that temporarily change colour after exposure to ultraviolet light or, in some cases, strong sunlight. Unlike fluorescence, which is only visible while the ultraviolet light source is present, tenebrescence produces a reversible colour change that remains visible after the ultraviolet light has been removed before gradually returning to the mineral's original appearance.\u003c\/p\u003e\n\u003cp data-start=\"853\" data-end=\"1293\"\u003eAlso known as \u003cstrong data-start=\"867\" data-end=\"895\"\u003ereversible photochromism\u003c\/strong\u003e, tenebrescence is a rare optical property found in only a small number of mineral species. The effect occurs when ultraviolet light temporarily alters the electronic structure of specific atoms or defects within the crystal lattice, producing a visible change in colour. Over time, exposure to normal visible light or simply the passage of time causes the mineral to return to its original colour.\u003c\/p\u003e\n\u003cp data-start=\"1295\" data-end=\"1619\"\u003eThe best-known example of tenebrescence is \u003cstrong data-start=\"1338\" data-end=\"1352\"\u003eHackmanite\u003c\/strong\u003e, a variety of sodalite renowned for its dramatic and repeatable colour changes. Other minerals may also exhibit tenebrescent behaviour under specific geological or chemical conditions, making these specimens highly sought after by collectors and mineral enthusiasts.\u003c\/p\u003e\n\u003cp data-start=\"1621\" data-end=\"1878\"\u003eTenebrescent minerals may also fluoresce under \u003cstrong data-start=\"1668\" data-end=\"1686\"\u003eLong Wave (LW)\u003c\/strong\u003e, \u003cstrong data-start=\"1688\" data-end=\"1708\"\u003eMedium Wave (MW)\u003c\/strong\u003e or \u003cstrong data-start=\"1712\" data-end=\"1731\"\u003eShort Wave (SW)\u003c\/strong\u003e ultraviolet light. The reversible colour change is an additional optical property and should not be confused with fluorescence or phosphorescence.\u003c\/p\u003e\n\u003cp data-start=\"1880\" data-end=\"2227\"\u003eOur collection includes specimens from recognised mineral localities around the world. Where testing has been carried out, each product listing identifies the ultraviolet wavelength used, the observed colour change and any accompanying fluorescent behaviour, providing collectors with a complete understanding of the specimen's optical properties.\u003c\/p\u003e\n\u003cp data-start=\"2229\" data-end=\"2494\"\u003eWhether you are expanding a specialist fluorescent mineral collection, studying mineral optics or searching for specimens with exceptional natural phenomena, tenebrescent minerals offer one of the most fascinating and interactive optical behaviours found in nature.\u003c\/p\u003e\n\u003ch3 data-section-id=\"2j84jm\" data-start=\"2496\" data-end=\"2534\"\u003eWhy Collect Tenebrescent Minerals?\u003c\/h3\u003e\n\u003cul data-start=\"2536\" data-end=\"2946\"\u003e\n\u003cli data-section-id=\"18wst3r\" data-start=\"2536\" data-end=\"2603\"\u003eObserve reversible colour changes following ultraviolet exposure.\u003c\/li\u003e\n\u003cli data-section-id=\"972zuo\" data-start=\"2604\" data-end=\"2683\"\u003eLearn the difference between fluorescence, phosphorescence and tenebrescence.\u003c\/li\u003e\n\u003cli data-section-id=\"8akleg\" data-start=\"2684\" data-end=\"2746\"\u003eExplore the science of reversible photochromism in minerals.\u003c\/li\u003e\n\u003cli data-section-id=\"109jsr4\" data-start=\"2747\" data-end=\"2820\"\u003eIdeal for advanced collections, museums and educational demonstrations.\u003c\/li\u003e\n\u003cli data-section-id=\"hoaedj\" data-start=\"2821\" data-end=\"2878\"\u003eClearly documented tenebrescent behaviour where tested.\u003c\/li\u003e\n\u003cli data-section-id=\"1r6cafy\" data-start=\"2879\" data-end=\"2946\"\u003eResponsibly sourced specimens from recognised mineral localities.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2948\" data-end=\"3181\"\u003eAt GeoFossils, we provide carefully selected mineral specimens supported by accurate mineralogical information, helping collectors, educators and enthusiasts explore the remarkable optical behaviours found within the mineral kingdom.\u003c\/p\u003e","products":[],"url":"https:\/\/www.geofossils.com\/collections\/tenebrescent-minerals.oembed","provider":"GeoFossils","version":"1.0","type":"link"}