geode

• Pierre ou nodule minéral creux, souvent de forme sphérique, dont la cavité interne est généralement tapissée de cristaux ou d'une autre substance minérale.

A hollow, often spherical rock or mineral nodule whose interior cavity is typically lined with crystals or other mineral matter.

1. Hollow rock with crystalsC1formalscientific

   A hollow, usually spherical rock or mineral nodule, the cavity of which is lined with crystals or other mineral matter.

   géode

   • The geode was split open to reveal a stunning array of amethyst crystals.
   • Collectors prize geodes for their beautiful internal crystal formations.
   • Geodes often form in volcanic or sedimentary rock environments.