{"product_id":"glendonite-calcite-ps-after-ikaite-2678-55","title":"GLENDONITE, Calcite ps after ikaite, Henrietta, Tasmania, Australia","description":"\u003csection id=\"mwAQ\" data-mw-section-id=\"0\"\u003e\n\u003cp\u003eGlendonite, a captivating mineral pseudomorph located in Tasmania, is predominantly discovered in marine mudstones dating back to the Permian period. These distinctive star-shaped crystal formations initially originated from the mineral ikaite, which is known to form exclusively in near-freezing aquatic environments. As temperatures rose, the ikaite crystals either dissolved or expelled their water, transforming into calcite. Glendonites function as significant geological time capsules, providing tangible proof of ancient ice ages that occurred during the Permian period when Tasmania was a component of the supercontinent Gondwana.\u003cbr\u003e\u003cbr\u003e\u003cspan\u003eGlendonites are the pseudomorphs of crystals and crystal clusters which grew in organic rich mud on the sea floor when the temperature was below 5 degrees Celsius. As the temperature rose and the original crystals dissolved, the space that they had occupied was colonised by harder minerals such as iron carbonate.\u003c\/span\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003eIkaite is the mineral designation for the hexahydrate form of calcium carbonate, represented as CaCO3·6H2O. This mineral typically forms steep or spiky pyramidal crystals, which are often arranged radially and can vary in size from small thumbnail aggregates to large prominent spurs. Ikaite exists only in a metastable state and quickly decomposes by losing most of its water content when taken out of near-freezing water. This so-called \"melting mineral\" is more widely recognized through its pseudomorphs.\u003c\/p\u003e\n\u003cp\u003eAlthough generally regarded as a rare mineral, its scarcity is likely attributed to the challenges associated with preserving samples. Ikaite was first identified in nature by the Danish mineralogist Pauly in the Ikka Fjord in southwest Greenland, near Ivittuut, which is known for its notable cryolite deposit.\u003c\/p\u003e\n\u003c\/section\u003e\n\u003cp\u003eThe existence of ikaite can be traced throughout geological history via the identification of pseudomorphs of other calcium carbonate forms that have replaced it.  While it may be challenging to definitively identify the original mineral for each specimen, there is substantial evidence suggesting that ikaite serves as the precursor for most of the following locality names associated with pseudomorphs:\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eGlendonite, named after its type locality, Glendon, New South Wales, Australia.\u003c\/strong\u003e\u003cbr\u003eThinolite, (Gr. Thinos = shore) discovered in the tufa deposits of Mono Lake, California, US\u003cbr\u003eJarrowite, originating from Jarrow, Northumberland, UK\u003cbr\u003eFundylite, found in the Bay of Fundy, Nova Scotia, Canada.\u003cbr\u003eGersternkorner, (Ger. = Barleycorn)\u003cbr\u003eGennoishi, (Jp. = hammerstones)\u003cbr\u003eMolekryds, (Dan. = Mole Cross), located on Mors Island, Jutland, Denmark.\u003cbr\u003ePseudogaylussite (named for its resemblance to Gaylussite)\u003cbr\u003eWhite Sea hornlets, found in the White Sea and Kola peninsula.\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cstrong\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/p\u003e","brand":"Crystals2Collect A.C.N 651.525.727 Pty Ltd","offers":[{"title":"55 55 22 31 \/ Henrietta TASMANIA \/ 2678-55","offer_id":52824610734356,"sku":"2678-55","price":85.0,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0706\/2047\/9764\/files\/20260722_115311.jpg?v=1784685472","url":"https:\/\/crystals2collect.com\/products\/glendonite-calcite-ps-after-ikaite-2678-55","provider":"Crystals2Collect ","version":"1.0","type":"link"}