I've got some rough flowering tube onyx. The material is beautiful, with fantastic patterns, and I'd like to slab it and cab it.

However, like most specimens of this type, the material has a lot of fractures.

What is an effective way to stabilize the material for slabbing?

2 Answers 2


You may have some luck with stabilizing it as though it was a slab. Using an epoxy in acetone method:

  1. Dissolve epoxy in acetone
  2. Submerge rough stone in the epoxy acetone mixture
  3. Seal up container so acetone does not evaporate
  4. Leave in mixture for at least a week
  5. Remove from acetone and let dry for at least another week

The important detail is this method relies on diffusion. When you have a slab your path length is relatively short, so the epoxy can diffuse in fairly quickly (days). As you make the material thicker the time increases. If you have a piece of rough that is fairly narrow in one dimension, you're in luck, treat it as a slab, diffusion won't be slowed down by rough edges, indeed it will be slightly faster. Where you're going to run into problems is with a thick piece of rough material that resembles a sphere. In this situation you may want to go at it in multiple passes as follows:

Let's say that your rough material is sphere with a diameter of six inches. Additionally you've determined that you can "completely" stabilize a slab that is one inch thick.

If you follow the same procedure with the rough material, you can "completely" stabilize the outer 1/2 inch of it. At which point you could cut off slabs as circles of a sphere:

circle of a sphere

of 1/2 inch thickness. The process could be repeated to allow for a second, larger, slab to be produced.

I would probably sacrifice the first layer, as it is typically irregular to begin with, making a poor slab. Or, because I am impatient, I would slab the rough and accept what breaks as broken and stabilize the usable parts as slabs.

Note: It has been years since I've made a cab and my knowledge of stabilization techniques is from research only, I have not tried these techniques myself.


Use resin to encase it and help it from falling apart. Yes it is an epoxy a two part to mix so it hardens but the resin Not glue will not yellow.

  • 1
    While this looks promising, this is both a very meager answer and a duplicate of the accepted answer. If you can expand on this (and maybe use proper punctuation), this could be a helpful addition to the other answer while ensuring it also answers the question independently.
    – Joachim
    Dec 5, 2020 at 8:36
  • An objective of the site's Q&A format is to have each answer contribute a solution not already covered. The mechanism for agreeing with an existing answer or recognizing that it contributes value is to upvote that post. Supplementing an existing answer with minor or tangential information that isn't a new solution can be done in a comment. Posts that just duplicate exiting information are viewed as noise that dilutes the ability of readers to efficiently find useful information. These tend to attract downvotes or get deleted. Consider expanding this into a unique solution or deleting it.
    – fixer1234
    Dec 5, 2020 at 18:22

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