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
Derived Forms
Inflected Forms
Nouns
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.
See Examples For:
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
After pouring hot aluminum into one of her stick-shaped molds and letting it cool in a pile of dirt, a participant took a ball-peen hammer and cracked open the rough silicate mold, like a geode.
From Los Angeles Times ● May 28, 2024
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
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
We nailed them on the wall above our beds, and that was where I kept my geode.
From "The Glass Castle" by Jeannette Walls
Each Rock Box includes a curated selection of high-quality crystals, rough rock, agates, geodes, gem collectibles and more.
From Seattle Times ● Nov. 16, 2023
The stalls around him showcased towering display pieces: rose quartz boulders, massive amethyst geodes.
From The Guardian ● Sep. 17, 2019
In addition to geodes, they amassed fossils of trilobites, ferns and fishes, as well as an authentic poison blow gun from the Amazon that includes a piranha jaw to sharpen the darts.
From New York Times ● Sep. 19, 2018
As a jazzy tune played over a boombox, they passed a few amethyst geodes and approached a large glass case displaying rocks with magnets affixed to them.
From The Verge ● Jun. 25, 2018
My favorite rocks to find were geodes, which Monyaid came from the volcanoes that had erupted to form the Tuscarora Mountains millions of years ago, during the Miocene period.
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.
