# How to identify a geode.. definitely MMPS

**URL:** <https://boards.straightdope.com/t/how-to-identify-a-geode-definitely-mmps/1020810>\
**Category:** Miscellaneous and Personal Stuff I Must Share\
**Created:** [July 13, 2025, 9:22am UTC](https://boards.straightdope.com/t/how-to-identify-a-geode-definitely-mmps/1020810 "2025-07-13T09:22:15Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![scudsucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scudsucker/32/14101_2.png) [@scudsucker](https://boards.straightdope.com/u/scudsucker)\
**Post date:** [July 13, 2025, 9:22am UTC](https://boards.straightdope.com/t/how-to-identify-a-geode-definitely-mmps/1020810/1 "2025-07-13T09:22:15Z")

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Backstory: I helped out a friend with moving house, she gave me a small quartz (?) rock as a thank-you - she’s not exactly wealthy, and I did the move for free (with her help). I don’t know the backstory, but I am pretty confident she was given it as “a geode” and gave me something she thought was a good gift.

Anyway. I now have a 4cm x 3cm x 2cm irregular rock. It looks like quartz to me but I am no minerologist. It is quite worn on the surface, but I think I can see worn down crystals on the surface.

My kids, aged 10 and 7 3⁄4 are interested in many things, but science and rocks are amongst them, so if this is a geode, I would like to get it cut open.

So, if some geologist suggests it is worth taking to a place that can cut it open, I’ll do that. I have quite a lot of doubt that it is anything but a common or garden rock.

Pics

> **[20250713-110026 hosted at ImgBB](https://ibb.co/7JL1zRKD)**
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> Image 20250713-110026 hosted in ImgBB

> **[20250713-110018 hosted at ImgBB](https://ibb.co/B5r4ZrxW)**
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> Image 20250713-110018 hosted in ImgBB

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**Author:** ![Elmer\_J.Fudd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/elmer_j.fudd/32/1211_2.png) [@Elmer\_J.Fudd](https://boards.straightdope.com/u/Elmer_J.Fudd)\
**Post date:** [July 13, 2025, 2:18pm UTC](https://boards.straightdope.com/t/how-to-identify-a-geode-definitely-mmps/1020810/2 "2025-07-13T14:18:25Z")

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From what I recall, the biggest indicators are weight and rattle. Find a rock of similar size and see if your’s weighs quite a bit less. If you hear something rattling inside, that’s almost a sure indicator. Geode or ordinary rock; what is the downside of slicing it open beside the expense?

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**Author:** ![scudsucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scudsucker/32/14101_2.png) [@scudsucker](https://boards.straightdope.com/u/scudsucker)\
**Post date:** [July 13, 2025, 2:50pm UTC](https://boards.straightdope.com/t/how-to-identify-a-geode-definitely-mmps/1020810/3 "2025-07-13T14:50:52Z")

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There is no rattle.

There are a couple of places that sell rocks, from tumbled pebbles up to 6 foot tall geodes in my city, so maybe I ask for an assay - or maybe they could just cut it, I don’t have equipment. Nothing to risk except mild disapointment!

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**Author:** ![Elmer\_J.Fudd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/elmer_j.fudd/32/1211_2.png) [@Elmer\_J.Fudd](https://boards.straightdope.com/u/Elmer_J.Fudd)\
**Post date:** [July 13, 2025, 2:59pm UTC](https://boards.straightdope.com/t/how-to-identify-a-geode-definitely-mmps/1020810/4 "2025-07-13T14:59:12Z")

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Do it yourself.

[![](https://img.youtube.com/vi/VAu4cjS7d08/maxresdefault.jpg "Easiest Way To Break Your Own Geode Hack") ](https://www.youtube.com/watch?v=VAu4cjS7d08)