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 ...

Sparkling hollows filled with lustrous crystals, dubbed geodes, are often perceived as small objects that can fit comfortably on a bookshelf. But some are more like gigantic cathedrals filled with a ...