Cleaning Agates with Iron Out: A Beginner’s Guide

Agates can be a challenge to clean up. You might find them covered or stained, and no amount of scrubbing with a brush will make take off the bad rust staining and make them look good. In this article, we’ll cover cleaning agates with Iron Out, at a beginner’s level.

Supplies You Will Need To Use Iron Out To Clean Rocks

Iron Out in its various forms (liquid and/or powder) is corrosive and damaging to your skin, eyes, lungs, and other mucous membranes. You’ll want to set up your cleaning station with this in mind.

Here’s what we recommend for your set up:

  • Assemble your materials and plan to keep your rocks/solution in a well ventilated area, away from your living space, your family, and pets.
  • Wear googles or a face shield to protect your face and eyes while handling the Iron Out solution.
  • Wear gloves and other clothing to protect your skin while handling the Iron Out solution.
  • Don’t set yourself up to breath in the fumes or the powdered form.

Here’s the items we recommend that you assemble:

  • Vessel for holding the rocks and solution–we like something with a flat bottom that is clear, so you can easily see the rocks from all sides, but others use a simple bucket or plastic container. I like using a bigger container so that the rocks can be spread out a bit.
  • Iron Out (liquid or powdered form–more discussion below)
  • Agates you want to clean up
  • Distilled water
  • Tap Water
  • Dish soap
  • Small scrub brush
  • Mixing utensil
  • Slow cooker (optional)

Which Kind of Iron Out to Use?

Iron Out comes in both liquid and powdered form, as well as a version specialized for Automatic Toilet Bowl Cleaning and Outdoor. If you check the Iron Out product listing sheets, you’ll see that the ingredients list actually varies quite a bit.

When looking at the liquid formulation of Iron Out, it notes that the primary ingredient is oxalic acid.

The chemical that we are looking to utilize on agates to remove the brown stains is oxalic acid, and this is why we recommend that you use Iron Out. People utilize the powdered version as well as the liquid and report good results.

But ultimately, any product that contains oxalic acid in some form will probably work for you.

Further, you’ll also see if you cruise some of the rockhounding forums that folks used to use Super Iron Out, which does not seem to be available on the market for purchase any longer, and it does not really seem to differ in any significant way from the Iron Out currently available on the market.

How Much Iron Out To Use to Clean Agates?

The amount of Iron Out you will need will depend upon how many agates (and how big they are) you want to clean. We don’t think that precise measurements are necessary (between how much water and how much Iron Out).

But in general, we think it is a good idea to keep track of how much you used, versus how much water, so that you can repeat the solution in the future or tinker with it.

If this is your first time, start with half gallon of water and half a pound of oxalic acid/Iron Out. Mix the solution by adding the Iron Out to the water (and not the other way around).

Steps to Clean Agates

  1. Rinse the agates, then scrub with dish soap and small brush, then rinse again.
  2. Place the agates in the bottom of the chosen vessel.
  3. Pour the oxalic acid/Iron Out mixture over the top of the rocks until fully covered.
  4. Set aside for three days uncovered, checking every day to see the progress of the rocks.
  5. Use gloves to remove the rocks from the solution after three days and rinse.

If the stone is not cleaned up enough, return it to the solution and let it sit for another 1-3 days. Check the rocks again. If you aren’t satisfied, return it to the solution. Feel free to mix up a new solution of the Iron Out if the original solution starts to get very dark.

Once you are satisfied with the progress of the stone, remove it from the oxalic acid solution, rinse it, scrub again with dish soap, rinse, then let it fully dry out.

Some folks leave their agates as they are, while others like to rub the cleaned up agates with mineral oil. Still others like to heat up the mineral oil covered agates in the oven or microwave.

Heat Can Speed Up The Process of Cleaning Agates with Iron Out

Leaving agates in the garage in the oxalic acid solution for weeks is alright for some, but we’ve seen folks clean up their agates quickly using Iron Out and a small but consistent source of heat.

Some folks put their solutions out in the sun, while others put theirs in a pan on a hot plate on low.

A decent alternative to using the kitchen stove is with using a slow cooker, definitely one that is not to be used to cook food ever again in the future.

Place the agates and the oxalic acid solution in the slow cooker, which should be set on the lowest setting (‘warm’). Let the agates cook uncovered or vented for 24 hours, and definitely don’t breath any fumes. Don’t boil it.

After 24 hours, remove the rocks from the solution and place them cold distilled water. Soak for several hours, changing the water frequently.

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Still have questions about cleaning up the rocks you’ve found? Check out our Knowledge Vault for more informational articles for rock hunters and collectors.