ナショナルジオグラフィックのインスタグラム(natgeo) - 1月29日 07時49分

Photos by Robbie Shone @shonephoto | These are very rare small cave formations called cryogenic calcite crystals (CCCs). They form in caves when water enters from the surface and then freezes and turns to ice. In the freezing process, the increasingly smaller pool of water becomes more and more enriched in salts (ions) to the point that the pool becomes supersaturated and these calcite crystals then form. CCCs are increasingly studied by scientists to establish when a cave contained ice. These CCCs come from England, where there are no ice caves today.

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