Calcite after Ikaite (formerly Gaylussite) (''floater'' specimen) (ex Dr. Wouter van Tichelen Collection)

Item Description

This piece is a classic old Russian "pineapple"-esque pseudomorph of cream colored Aragonite which (according to the label) has replaced Gaylussite, which is now called Ikaite. We refer to an entry from the "Best of Pseudomorphs" page on mindat.org which states: "Calcite after Ikaite specimens have in some literature been given the name glendonites and other names as well. This large group of worldwide Calcite pseudomorphs after Ikaite have been described under a variety of different individual names, as will as being assigned various parentage. Many were consolidated under the name "Pseudogaylussite"(Von Calker 1897). However E. S. Dana(1884) while studing similar Calcite pseudos from Nevada, believed the precursor would be a mineral yet to be discovered. That material was finally located in a Greenland Fjord(Pauly 1963). It proved to be a thermally unstable, Calcium carbonate hexahedrite. He named it Ikaite, after the fjord. As it was a massive mineral, it did not create much interest among pseudomorph collectors, except in Russia(Kaplin 1978). The first Ikaite crystals were found in drill cores, extracted of the Bransfield Strait, Antarctica. At temperatures above 4-5 degrees Celsius, the Ikaite separated into a "Mush" of tiny Calcite crystals and water. Suess(1982), on the basis of crystal shape and the alteration to Calcite, he declared Ikaite to be the missing precursor for this group of pseudomorphs. He referred to the pseudos as being "Glendonites", a term being used for specimens of this type from nearby Australia. Some specimens show up due to the breakup of old collections. Russian and Australian pseudomorphs are still found on-line." This piece is a great example of these fine old classics featuring dozens of very sharp "dog tooth"-shaped crystals measuring up to 1.1 cm long. The piece is in very good condition, and is essentially a complete "floater", crystallized on all sides. From the prestigious pseudomorph collection of Dr. Wouter van Tichelen of Belgium.