Definition of geode in US English:



  • 1A small cavity in rock lined with crystals or other mineral matter.

    • ‘Some visitors gather around the sparkling amethyst geodes or the shining pyrite crystals.’
    • ‘Sphalerite in crystals to 8 cm and cleavage masses to 30 cm across occurs in geodes of the well-known southeastern Iowa localities, such as those around Keokuk.’
    • ‘Colorless quartz crystals lining geodes have also been found at approximately 300 feet below the trail at the South Overlook locality.’
    • ‘Most of the thirty-two pages on Moroccan agate are color plates of superb geodes with fantastic patterns and inclusions.’
    • ‘One case has a selection of crystal-lined geodes, several filled with amethyst, from the Josini area of northern KwazuluNatal in South Africa.’
    • ‘Mordenite lines most of the geodes as the typical fine hairlike crystals of the species.’
    space, chamber, hollow, hole, pocket, pouch
    View synonyms
    1. 1.1 A rock containing a cavity lined with crystals or other mineral matter.
      • ‘People love to do camping here because of the fascinating aura and to grab 15 pounds of agates, geodes and quartz that anyone can gather and take to home.’
      • ‘Two adjacent geodes from the same piece of shale could be cracked open, and one would be lined with brown calcite, the other with quartz.’
      • ‘‘This is a once-in-a-lifetime opportunity,’ exclaimed a collector from the Keokuk area who was working beside me splitting geodes out of shale.’
      • ‘Do I not take responsibility for my stress when I lift the geode and consciously transform the stress energy into something healthier for my physical body?’
      • ‘It's centered around this hill with all these geodes, and a stone archway at the top.’
      • ‘In the extreme and startling contrast between its outer and inner life, it resembles some kind of weird rock or geode that, split open, reveals a spectacular mineral formation.’
      • ‘It's a teeny one… but like all geodes there is a whole different world inside.’
      • ‘It is a geode having a small U-shaped cavity crammed with tiny quartz crystals.’
      • ‘He opened one of the largest geodes and gave half to Hart.’
      • ‘Joy likens the house to a geode, the coarseness of the rough steel exterior contrasting with the refinement of the interior.’
      • ‘They are different from geodes in that they have a solid center, often displaying a great contrast between the rocky shell of brown and the milky white and clear crystal center.’


Late 17th century: via Latin from Greek geōdēs ‘earthy’, from gē ‘earth’.