“It was surprising to find these very low temperatures,” Arduin Rode says. Researchers studying amethyst geode formation in Brazil’s lava flows have proposed temperatures below 100 ° ...

People view the 12-foot tall amethyst ... Most geodes are small as they form inside gas bubbles in lava rocks. Only in rare cases is lava so rich in gases that very large voids form or larger ...

University of Göttingen researchers uncovered that Uruguay’s amethyst geodes formed from low-temperature groundwater fluids, proposing a groundbreaking formation model. New research from the ...