{"product_id":"gypsum-sand-selenite-rose-from-a-dry-lake-near-ica-ica-province-peru-hand-display-specimen-copy","title":"gypsum - unusual sand selenite from a dry lake in the Atacama Desert, Ica Province, southern Peru - hand\/display specimen","description":"\u003cp\u003e\u003cspan style=\"color: rgb(134, 4, 4);\"\u003e\u003cb\u003eSelenite - gypsum sand rose    \u003c\/b\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eCaSO\u003c\/b\u003e\u003c\/span\u003e\u003cspan class=\"s2\"\u003e\u003cb\u003e\u003csub\u003e4\u003c\/sub\u003e\u003c\/b\u003e\u003c\/span\u003e\u003cspan class=\"s3\"\u003e\u003cb\u003e \u003c\/b\u003e\u003c\/span\u003e\u003cspan class=\"s4\"\u003e\u003cb\u003e∙\u003c\/b\u003e\u003c\/span\u003e\u003cspan class=\"s5\"\u003e\u003cb\u003e \u003c\/b\u003e\u003c\/span\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003e2H\u003c\/b\u003e\u003c\/span\u003e\u003cspan class=\"s2\"\u003e\u003cb\u003e\u003csub\u003e2\u003c\/sub\u003e\u003c\/b\u003e\u003c\/span\u003e\u003cspan class=\"s1\"\u003e\u003cb\u003eO\u003c\/b\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: rgb(134, 4, 4);\"\u003e\u003cb\u003eSelenite gypsum sand \"roses\" form in seasonal desert lakes as they dry. \u003c\/b\u003e\u003c\/span\u003e\u003cspan style=\"color: rgb(134, 4, 4);\"\u003e\u003cb\u003eSelenite is typically transparent, but when it crystallizes in sandy conditions it forms rosettes of flattened crystals, the rose “petals,” which are either encrusted with sand or with sand embedded throughout. \u003cmeta charset=\"utf-8\"\u003eThe color of the gypsum crystals depends on the color of the sand in that dry lake. These Peruvian examples were recently discovered and are particularly attractive.\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: rgb(134, 4, 4);\"\u003e\u003cb\u003eUnlike the white-edged desert roses you see for sale in rock shops, these are unaltered and completely natural. Since gypsum has two attached water molecules, mineral dealers cook selenite roses with a weed burner to drive off the water, turning the edges of the crystals white. They are not found like this naturally, and we prefer that students see this mineral in unaltered form.\u003cspan class=\"Apple-converted-space\"\u003e \u003c\/span\u003e\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: rgb(134, 4, 4);\"\u003e\u003cb\u003eThe field photo shows selenite roses from Mexico being burned to make the edges of the flattened crystals white. This is also how plaster is made. Gypsum is heated to above 130˚ Celsius to drive off roughly 75% of the water. When powdered, it becomes plaster. When water is added, the plaster rehydrates to become gypsum. Between two thick paper sheets, it becomes wallboard.\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: rgb(134, 4, 4);\"\u003e\u003cb\u003eUnburned Mexican sand selenite roses are very difficult to find. Geode slices from Brazil are also altered by dying them in unnatural shades of red or blue, and the unwitting buyer finds them attractive, though altered specimens are not what a geology student should see. \u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: rgb(134, 4, 4);\"\u003e\u003cb\u003eThese unusual and attractive Peruvian examples are very good, carefully collected and unaltered. These were discovered in 2025.\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"color: rgb(0, 0, 0);\"\u003e\u003cb\u003eThe pencil is 5 1\/2 inches long, for scale.\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cspan class=\"s1\" style=\"color: rgb(255, 42, 0);\"\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 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\u003e\u003cspan style=\"color: #ff0000;\"\u003e\u003cb\u003eMaking multiple purchases?\u003c\/b\u003e\u003c\/span\u003e\u003cspan\u003e\u003cb\u003e Click on the \"combine shipping\" button in the shopping cart. We'll send an invoice with combined shipping. A link in that invoice will bring you back to checkout, no hassle.\u003c\/b\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cspan class=\"s1\" style=\"color: rgb(255, 42, 0);\"\u003e\u003cb\u003eShipping:\u003c\/b\u003e\u003c\/span\u003e\u003cb\u003e By Priority Mail or USPS Ground Advantage, whichever is cheaper, unless we find a better rate. \u003c\/b\u003e\u003cb\u003eClick \u0026gt; \u003c\/b\u003e\u003ca href=\"Shipping:%20Priority%20Mail%C2%A0package.%20%20Click%20\u0026gt;%20here%20\u0026lt;%20for%20shipping%20rates.%20See%20Note!%20on%20the%20shipping%20page.%20Use%20back%20button%20to%20return%20to%20this%20page.\"\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 \u003c\/b\u003e\u003cspan class=\"s1\" style=\"color: #ff2a00;\"\u003e\u003cb\u003eNote!\u003c\/b\u003e\u003c\/span\u003e\u003cb\u003e on the shipping page. Use back button to return to this page.\u003c\/b\u003e\u003c\/p\u003e","brand":"Geological Specimen Supply","offers":[{"title":"Default Title","offer_id":42705182195799,"sku":null,"price":25.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0960\/7650\/files\/sandselenitePeruH_D25pcl.jpg?v=1776318820","url":"https:\/\/geologicalspecimensupply.com\/products\/gypsum-sand-selenite-rose-from-a-dry-lake-near-ica-ica-province-peru-hand-display-specimen-copy","provider":"Geological Specimen Supply","version":"1.0","type":"link"}