<p>I have a nice geode sample that is sadly structurally unsound, and I am looking for a solution to make it sturdier so I don't run as much of a risk of it breaking on me. I have a separate geode that has a black material on it that seems like it makes said geode more structurally sound. What material is it? I have tried googling to find an answer, but I have been unable to find a proper answer. I am looking to figure out what it is so I may get some to use on my other geode.</p>
<p>The material is rather sturdy, heavy, and cool to the touch. The lower &quot;mass&quot; of the dark stuff feels like concrete, though I can not tell what the coating on the outside is made of.</p>
<p><a href="https://i.sstatic.net/PKYtx.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/PKYtx.jpg" alt="Geode_Cathedral_with_material" /></a></p>
<p><a href="https://i.sstatic.net/mBKYn.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/mBKYn.jpg" alt="Another_Picture_of_it" /></a></p>

CC BY-SA 4.0
2022-05-19T05:46:07.750Z
It's hard to identify from the picture whether that's part of the rock or something man-made cast around it.  I suspect the only way people will be able to answer is if that is a standard thing done to geodes, and someone is familiar with the practice.
fixer1234
CC BY-SA 4.0
2022-05-19T06:36:05.487Z
@fixer1234 I am pretty sure it is something applied to the geode to keep it sturdier. I tried googling around to find an answer, but I don't know the proper keywords to look up to try and find my answer. I will update my answer with some extra description though.
The Man
CC BY-SA 4.0
2022-05-19T06:54:47.010Z
I tried a quick Google search on "geode protection". It produced a bunch of hits about the magical properties of how geodes protect you.  :-)
fixer1234
CC BY-SA 4.0
2022-05-19T07:07:26.580Z
@fixer1234 Yeah, that is the problem I was coming up with lol. If I try to look up anything about fortifying or protecting geodes I get that type of stuff, and if I try to look up "geode black paint" I get articles about telling if they are real or not (as in, painted colors and such).
The Man
CC BY-SA 4.0
2023-02-14T00:21:29.630Z
I took another look at this. Some geodes do have a black exterior with a light color inside. If it's hard and cold to the touch, it sounds "mineral" rather than something like resin. In the top picture, it looks like the outer layer is gray, and only the surface is black. It's possible that it's a thin coating of something just to make the outside black and shinier. But that wouldn't offer any protection. Cement is brittle and has no tensile strength, so coating the geode with that wouldn't offer any protection. That might be the actual exterior of that geode. (cont'd)
fixer1234
CC BY-SA 4.0
2023-02-14T00:21:35.353Z
One way geodes form is inside lava, which could explain the surface texture. If the other geode isn't structurally sound, there are some things that could strengthen it, like a layer of fiberglass (often put on the underside of marble or quartz slabs used for table tops and counters. But it would look crappy and unnatural.
fixer1234
<technique-identification><material-identification><lapidary>
What is holding this geode together and how?
The Man
# What is holding this geode together and how?

(Asked by: username_0 on 2022-05-19)

I have a nice geode sample that is sadly structurally unsound, and I am looking for a solution to make it sturdier so I don't run as much of a risk of it breaking on me. I have a separate geode that has a black material on it that seems like it makes said geode more structurally sound. What material is it? I have tried googling to find an answer, but I have been unable to find a proper answer. I am looking to figure out what it is so I may get some to use on my other geode.

The material is rather sturdy, heavy, and cool to the touch. The lower "mass" of the dark stuff feels like concrete, though I can not tell what the coating on the outside is made of.

[![Geode_Cathedral_with_material](https://i.sstatic.net/PKYtx.jpg)](https://i.sstatic.net/PKYtx.jpg)

[![Another_Picture_of_it](https://i.sstatic.net/mBKYn.jpg)](https://i.sstatic.net/mBKYn.jpg)

**Tags:** technique-identification, material-identification, lapidary

> **Comments:**
> **username_1**: It's hard to identify from the picture whether that's part of the rock or something man-made cast around it.  I suspect the only way people will be able to answer is if that is a standard thing done to geodes, and someone is familiar with the practice.  
> **username_0**: @username_1 I am pretty sure it is something applied to the geode to keep it sturdier. I tried googling around to find an answer, but I don't know the proper keywords to look up to try and find my answer. I will update my answer with some extra description though.  
> **username_1**: I tried a quick Google search on "geode protection". It produced a bunch of hits about the magical properties of how geodes protect you.  :-)  
> **username_0**: @username_1 Yeah, that is the problem I was coming up with lol. If I try to look up anything about fortifying or protecting geodes I get that type of stuff, and if I try to look up "geode black paint" I get articles about telling if they are real or not (as in, painted colors and such).  
> **username_1**: I took another look at this. Some geodes do have a black exterior with a light color inside. If it's hard and cold to the touch, it sounds "mineral" rather than something like resin. In the top picture, it looks like the outer layer is gray, and only the surface is black. It's possible that it's a thin coating of something just to make the outside black and shinier. But that wouldn't offer any protection. Cement is brittle and has no tensile strength, so coating the geode with that wouldn't offer any protection. That might be the actual exterior of that geode. (cont'd)  
> **username_1**: One way geodes form is inside lava, which could explain the surface texture. If the other geode isn't structurally sound, there are some things that could strengthen it, like a layer of fiberglass (often put on the underside of marble or quartz slabs used for table tops and counters. But it would look crappy and unnatural.  

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## 0 answers

