{"product_id":"calcite-hot-pink-fluorescent-and-phosphorescent-calcite-smaller-cleavage-rhomb-from-the-challenger-cave-system-nuevo-leon-mexico-copy","title":"calcite - hot pink fluorescent and phosphorescent calcite - smaller cleavage rhomb from the Challenger Cave system, Nuevo Leon, Mexico (Copy)","description":"\u003cp\u003e\u003cspan style=\"color: rgb(123, 10, 10);\"\u003e\u003cb\u003eCalcite, CaCO\u003c\/b\u003e\u003cb\u003e\u003csub\u003e3, \u003c\/sub\u003e\u003c\/b\u003e\u003cb\u003eis an extremely common rock forming mineral. In pegmatites it forms large masses and it makes up some limestones almost entirely. It has a large variety of crystal forms, but these do not include the rhombus-shaped pieces that are sold as “calcite crystals.” The rhombs are produced by cleaving calcite in three directions between rows of atoms. \u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: rgb(123, 10, 10);\"\u003e\u003cb\u003eWhen calcite is free of impurities and is optically clear, it exhibits double refraction. When it is placed above a line drawn on paper and rotated, the drawn line doubles and becomes single depending on the angle of rotation. These are not clear enough to show double refraction.\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: rgb(123, 10, 10);\"\u003e\u003cb\u003eUnder\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e longwave\u003c\/span\u003e ultraviolet, these specimens fluoresce a bright hot pink. \u003cspan style=\"color: rgb(0, 0, 0);\"\u003eThe first photo shows this fluorescence.\u003c\/span\u003e The second photo compares the shortwave response of these specimens with others from the same cave system that fluoresce bright cool pink. The third photo shows the \u003cspan style=\"color: rgb(0, 0, 0);\"\u003eshortwave\u003c\/span\u003e phosphorescent glow, a weak bluish fluorescence and also a blue to white phosphorescence that extinguishes slowly enough to watch. This is described for each specimen below.\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: rgb(123, 10, 10);\"\u003e\u003cb\u003e\u003cstrong\u003eIn a phosphorescent substance, electrons that absorb energy slowly re-emit it, sometimes glowing for minutes or even hours as they return to their original energy states. Most phosphorescent compounds are fast emitters, however, with lifetimes on the order of milliseconds. You can watch this calcite extinguish as the atoms return to their normal energy state after exciting it with shortwave for a few seconds.\u003c\/strong\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: rgb(109, 3, 3);\"\u003e\u003cb\u003eThese clean sharp rhombs of colorless calcite are from the Challenger Cave system near Monterrey, Nuevo Leon, Mexico, a famous locality for fluorescent calcite that is now inaccessible. These were mined about five years ago. Once these are gone, that's it.\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: rgb(109, 3, 3);\"\u003e\u003cb\u003e\u003cmeta charset=\"utf-8\"\u003e \u003cspan style=\"color: #000000;\"\u003eYou will need a strong and well-filtered shortwave lamp to see the bluish fluorescence and  phosphorescent decay after the lamp is extinguished.  Much of this reaction to ultraviolet is directional - illuminate a rhomb from one direction and the reaction is strong, from another direction and it is not. The \u003cspan style=\"color: rgb(255, 0, 255);\"\u003ecool pink \u003c\/span\u003efluorescing specimens we have in stock exhibit stronger phosphorescence. \u003c\/span\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003epencil, no coins - phosphorescence is decent\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003epencil, 2 coins - phosphorescence is strong\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: #000000;\"\u003e\u003cb\u003eFor the pink fluorescence, any filtered ultraviolet flashlight - they are all long wave - will work. For a powerful response, we can recommend a longwave flashlight, complete with battery and charger, sold by Way Too Cool at\u003ca href=\"https:\/\/www.fluorescents.com\/products-jive-mini-uv-flashlight.html\"\u003e \u003c\/a\u003e\u003ca href=\"https:\/\/www.fluorescents.com\/products-jive-mini-uv-flashlight.html\" rel=\"noopener\" target=\"_blank\"\u003e\u003cspan style=\"color: rgb(43, 0, 255);\"\u003ehttps:\/\/www.fluorescents.com\/products-waltz-uv-flashlight.html\u003c\/span\u003e\u003c\/a\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: #000000;\"\u003e\u003cb\u003eFor the phosphorescence, we recommend The Triple, complete with batteries and a charger, from Way Too Cool that lets you see fluorescence in short, medium and longwave u\/v: \u003ca href=\"https:\/\/www.fluorescents.com\/products-the-triple.html\"\u003e\u003cspan style=\"color: rgb(43, 0, 255);\"\u003ehttps:\/\/www.fluorescents.com\/products-the-triple.html\u003c\/span\u003e\u003c\/a\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: #000000;\"\u003e\u003cb\u003eIf tiny rhombs would be useful in your classroom, let us know and we'll include some, though not of this calcite, for student experimenting and \u003c\/b\u003e\u003cb\u003eso you can demonstrate the calcium carbonate response to a drop of hydrochloric acid - it fizzes and releases carbon dioxide - without wrecking this example.\u003c\/b\u003e\u003c\/span\u003e\u003cspan style=\"color: #000000;\"\u003e\u003cb\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: #000000;\"\u003e\u003cb\u003e\u003cmeta charset=\"utf-8\"\u003eClick on an image to enlarge and click again to further enlarge. The pencil is 5 1\/2\" long, for  scale. \u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cspan style=\"color: #ff2a00;\" class=\"s1\"\u003e\u003cb\u003eSelect a specimen:\u003c\/b\u003e\u003c\/span\u003e\u003cb\u003e When more than one specimen is shown, you can select a particular specimen by telling us what is in the photo with it, a black and silver pen, a black mechanical pencil (it has an eraser), or one of those plus some number of coins, or you can let us make the selection.\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cspan style=\"color: rgb(255, 42, 0);\" class=\"s1\"\u003e\u003cb\u003eMaking multiple purchases?\u003c\/b\u003e\u003c\/span\u003e\u003cb\u003e\u003cspan style=\"color: rgb(255, 42, 0);\"\u003e \u003c\/span\u003eClick on the \"combine shipping\" button in the shopping cart. We'll send an invoice with combined shipping. It may not be instantaneous, since a human has to take a look and we might be out in the field during the day. A link in that invoice will bring you back to checkout, no hassle.\u003c\/b\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003e\u003cspan style=\"color: #ff2a00;\"\u003eShipping\u003c\/span\u003e:\u003c\/b\u003e\u003c\/span\u003e\u003cb\u003e By Priority Mail or USPS Ground Advantage, whichever is cheaper. Click \u0026gt; \u003c\/b\u003e\u003ca href=\"https:\/\/geologicalspecimensupply.com\/pages\/about-shipping\"\u003e\u003cspan class=\"s2\" style=\"color: #2b00ff;\"\u003e\u003cb\u003ehere\u003c\/b\u003e\u003c\/span\u003e\u003c\/a\u003e\u003cb\u003e \u0026lt; for shipping rates. See comment at \u003c\/b\u003e\u003cspan class=\"s1\" style=\"color: #ff2a00;\"\u003e\u003cb\u003eNote!\u003c\/b\u003e\u003c\/span\u003e\u003cb\u003e Use back button to return to this page.\u003c\/b\u003e\u003c\/p\u003e","brand":"Geological Specimen Supply","offers":[{"title":"Default Title","offer_id":44064497107031,"sku":null,"price":9.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0960\/7650\/files\/calciteNLhotpinklwu_v.jpg?v=1770626146","url":"https:\/\/geologicalspecimensupply.com\/products\/calcite-hot-pink-fluorescent-and-phosphorescent-calcite-smaller-cleavage-rhomb-from-the-challenger-cave-system-nuevo-leon-mexico-copy","provider":"Geological Specimen Supply","version":"1.0","type":"link"}