{"product_id":"calcite-mineral-specimen-linwood-mine-iowa-usa","title":"Calcite - Specimen","description":"\u003cp class=\"p1\" data-mce-fragment=\"1\"\u003e\u003cb data-mce-fragment=\"1\"\u003eLocality\u003c\/b\u003e: Linwood Mine, Buffalo, Iowa, U.S.A.\u003cbr data-mce-fragment=\"1\"\u003e\u003c\/p\u003e\n\u003cp class=\"p1\"\u003e\u003cstrong\u003eDescription\u003c\/strong\u003e: This calcite formed in a cave that was sealed underground for hundreds of millions of years. The Linwood Mine sits on the Iowa bank of the Mississippi River, just east of Buffalo, in Middle Devonian limestone laid down on the floor of a shallow sea. Before the Pennsylvanian period, groundwater dissolved caves and passages in this limestone along fractures and bedding planes. Geologists call these buried caves paleokarst.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eThe larger caves filled with river sediment, but many smaller openings in the lower Cedar Rapids limestone stayed open. Mineral-rich water lined them with crystals. Calcite grew there in several generations, switching between sharp, pointed crystals and blunter, blocky ones, alongside marcasite, barite and pyrite.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eLimestone has been quarried here since at least 1897. Linwood opened an open pit in 1918 and went underground around 1956. Today it is one of the largest underground limestone mines in the United States, working two levels and mining about 32 acres a year.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eThe mine is still active and is closed to collectors. Crystals are saved only when miners open a pocket during production, and Linwood calcite without dings is hard to find. Some Linwood calcite glows purple-magenta under midwave ultraviolet light. At about 20 cm across and 2.7 kg, this is a large cabinet piece from the locality.\u003c\/p\u003e\n\u003cp class=\"p1\"\u003eIn crystal traditions, calcite is associated with cleansing energy and prosperity.\u003c\/p\u003e\n\u003cp class=\"p1\" data-mce-fragment=\"1\"\u003e\u003cb data-mce-fragment=\"1\"\u003eChemical Composition\u003c\/b\u003e: \u003cmeta charset=\"utf-8\"\u003e\u003cspan data-mce-fragment=\"1\"\u003eCaCO₃\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"p1\" data-mce-fragment=\"1\"\u003e\u003cstrong\u003eChakra: \u003c\/strong\u003eAll\u003c\/p\u003e\n\u003cp class=\"p1\" data-mce-fragment=\"1\"\u003e\u003cb data-mce-fragment=\"1\"\u003eApproximate Size for 1 piece\u003c\/b\u003e: 20cm x 16cm x 6cm\u003cbr data-mce-fragment=\"1\"\u003e\u003cb data-mce-fragment=\"1\"\u003eApproximate Weight for 1 piece\u003c\/b\u003e: 2686g\u003cbr data-mce-fragment=\"1\"\u003e\u003c\/p\u003e\n\u003cp class=\"p1\" data-mce-fragment=\"1\"\u003e\u003cstrong data-mce-fragment=\"1\"\u003eQuantity\u003c\/strong\u003e: 1pc\u003c\/p\u003e\n\u003cp class=\"p1\" data-mce-fragment=\"1\"\u003e\u003ci data-mce-fragment=\"1\"\u003eWith this product, you will get the actual stone in the photograph. We do what we can to buy good quality products and price them honestly. The rocks may differ from the photos, but we hope we do them justice.\u003c\/i\u003e\u003c\/p\u003e","brand":"Iowa, U.S.A.","offers":[{"title":"Default Title","offer_id":42477757923498,"sku":"IOWACALCITERAW","price":600.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0601\/7158\/3658\/products\/Calcite-Iowa_2.jpg?v=1649888944","url":"https:\/\/rubblerockandgem.com\/fr\/products\/calcite-mineral-specimen-linwood-mine-iowa-usa","provider":"Rubble Rock And Gem","version":"1.0","type":"link"}