Crack open an unassuming stone, and you might just uncover a little conclave of crystals within. Their walls are glittering with quartz, amethyst, or calcite, protected by a hard shell that was shaped ...

Amethyst geodes—some stretching 5 m long—dot the ancient lava flows of Uruguay’s Los Catalanes mining area. The geodes contain calcite, colorless quartz, and agate, another quartz mineral. Large ...

People view the 12-foot tall amethyst geode from Uruguay hosted at the American Museum of Natural History in New York. Thanks to geological surveys and detailed chemical analysis, a team of ...

Amethyst is a violet variety of quartz that has been used as a gemstone for many centuries and is a key economic resource in northern Uruguay. Geodes are hollow rock formations often with quartz ...

Göttingen University researcher Fiorella Arduin Rode working in open pit mine of the study area, Los Catalanes mining district, northern Uruguay. Along with Ametista do Sul in southern Brazil, these ...

Taken by themselves, geodes are gorgeous, with the insides lined with crystals that add a sense of beauty and wonder to the rocks, and they become even more amazing when they are dinosaur eggs, as was ...

Millions of years ago, in present-day Uruguay, gas bubbles became trapped in magma as it hardened to rock; over time, these cavities morphed into amethyst-quartz-lined geodes. A dazzling ...

Geode is a type of sedimentary and volcanic rock that is hollow, vaguely circular rock, in which masses of mineral matter (which may include crystals) are sequestered. The term 'Geodes' was derived ...

Amethyst is a violet variety of quartz which has been used as a gemstone for many centuries and is a key economic resource in northern Uruguay. Geodes are hollow rock formations often with quartz ...