Cherry Blossom StonesThese lovely stones are found in a few rare areas in Japan, leading to their ni
Cherry Blossom StonesThese lovely stones are found in a few rare areas in Japan, leading to their nickname as “Cherry Blossom Stones” after the famous Japanese Cherry-Blossom Trees.They have a complicated origin. These rocks started out as shales – sedimentary rocks, probably deposited on the floor of an ancient ocean. As Japan grew, those shales were compressed and heated near magma chambers from the Japanese volcanic arc. That heat caused two chemical types of the mineral cordierite to form – the first crystal of cordierite formed and then 6 different cordierite crystals grew, radiating around the core.After those minerals formed, the rock sat there for a while and cooled off, but it was later reheated by another magmatic system. This time, the magma didn’t just add heat, it also added water from magmatic, hydrothermal fluids. Those fluids reacted with the cordierite and converted it into muscovite – a much shinier, if more friable, mineral.These rocks break easily but as you can tell they’re both fairly nice collectors items and quite rare due to the complicated sequence required to form them.-JBBImage credit: James St. Johnhttps://flic.kr/p/p1idTHRead more:http://www.mindat.org/min-1128.htmlhttps://www.wordnik.com/words/subhexagonalhttp://bit.ly/1LMffEU -- source link
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