geode
Americannoun
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a hollow concretionary or nodular stone often lined with crystals.
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the hollow or cavity of this.
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any similar formation.
noun
Other Word Forms
Etymology
Origin of geode
1670–80; < French géode < Latin geōdēs < Greek geṓdēs earthlike. See geo-, -ode 1
Explanation
On the outside, a geode looks like an ordinary rock, but when you break a geode open, it's full of crystals. Geodes are hollow rock formations with minerals, often quartz crystals, massed inside. A geode forms when minerals settle into a hollow in the earth (like an animal burrow) or inside volcanic rock bubbles. First, a hard shell is formed, and then the minerals grow toward the center of the geode, often forming crystals in the process. The Greek root, geodes, means "earth-like."
Vocabulary lists containing geode
In A Sedimental Mood: Rock and Gem Vocabulary
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Earth Science - Middle School
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Rocks and Minerals - Introductory
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Heyward co-hosted a fundraiser with his wife last week where Pratt was smudged with sage before standing in front of a giant amethyst geode to address about 125 people.
From The Wall Street Journal • May 21, 2026
Looking like a glittering cosmic geode, a trio of dazzling stars blaze from the hollowed-out cavity of a reflection nebula in this new image from NASA's Hubble Space Telescope.
From Science Daily • May 15, 2024
“This place is as good as it gets,” Losson said recently as he hoisted a small geode filled with quartz crystals.
From Los Angeles Times • Jul. 16, 2023
After every death, Nadia wakes up back in Maxine's cool bathroom with a glowing geode on the door and a gun-shaped door handle.
From Salon • Apr. 16, 2022
I wanted to bring my bike, but Mom said it was too big, so I brought my geode.
From "The Glass Castle" by Jeannette Walls
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
