<p>I found this rock today on my property. It looks similar to another rock I saw that was said to be a civil war cannon ball, however comments below suggest that it could be a geode.</p>

<ol>
<li>Are there any tests I can do <em>short of breaking it in half</em> to find out if it is a geode?</li>
<li>If I wanted to break it into two halves in a nice way (rather than smash it up into several random pieces) how might I do that?</li>
</ol>

<p><img src="https://i.sstatic.net/zgOCo.jpg" alt="possible geode?"></p>

CC BY-SA 4.0
2019-09-02T04:21:18.250Z
it is not a cannonball(they are made of iron)
trond hansen
CC BY-SA 4.0
2019-09-02T04:39:19.013Z
@trond hansen: It was actually quite common in some times/places to make cannonballs out of stone, though I think not in the US Civil War: https://en.wikipedia.org/wiki/Round_shot
jamesqf
CC BY-SA 4.0
2019-09-02T07:16:30.930Z
It's definitely not a cannon ball, it's not round enough. It looks very similar to some geodes I found in Oman many years ago. To  test if it is a geode, you have to break it open. Geodes are hollow inside and usually lined with pretty quartz crystals, but more rarely contain amethyst or opal.
Michael Walsby
CC BY-SA 4.0
2019-09-05T07:58:51.643Z
Rock identification requests are being phased out, so I've modified your question in order to make it more likely to be on-topic, then voted to reopen. *Welcome to Stack Exchange!*
uhoh
CC BY-SA 4.0
2019-09-06T18:52:50.387Z
The best thing would be to use an angle grinder, which is a portable electric tool for cutting through hard materials  If you can't find one, try a large hacksaw. One of your neighbours will probably have one.
Michael Walsby
<rocks><geode>
How can I find out if this is a geode without breaking it in half?
Linda Cash
# How can I find out if this is a geode without breaking it in half?

(Asked by: username_0 on 2019-09-02)

I found this rock today on my property. It looks similar to another rock I saw that was said to be a civil war cannon ball, however comments below suggest that it could be a geode.

1. Are there any tests I can do *short of breaking it in half* to find out if it is a geode?
2. If I wanted to break it into two halves in a nice way (rather than smash it up into several random pieces) how might I do that?

![possible geode?](https://i.sstatic.net/zgOCo.jpg)

**Tags:** rocks, geode

> **Comments:**
> **username_1**: it is not a cannonball(they are made of iron)  
> **username_2**: @username_1: It was actually quite common in some times/places to make cannonballs out of stone, though I think not in the US Civil War: https://en.wikipedia.org/wiki/Round_shot  
> **username_3**: It's definitely not a cannon ball, it's not round enough. It looks very similar to some geodes I found in Oman many years ago. To  test if it is a geode, you have to break it open. Geodes are hollow inside and usually lined with pretty quartz crystals, but more rarely contain amethyst or opal.  
> **username_4**: Rock identification requests are being phased out, so I've modified your question in order to make it more likely to be on-topic, then voted to reopen. *Welcome to Stack Exchange!*  
> **username_3**: The best thing would be to use an angle grinder, which is a portable electric tool for cutting through hard materials  If you can't find one, try a large hacksaw. One of your neighbours will probably have one.  

---

## 0 answers

