How To Clean Rocks And Minerals (Tips and Techniques)

how to clean rocks minerals crystals

You’ll have to clean your own rocks and minerals if you dig them up. Dirt and buildup may be removed with running water, but the trick is to do so without harming the stones.

Rocks and minerals may be cleaned in a variety of methods, and each one is different.

Let’s get started, and I’ll teach you how to properly clean rocks and minerals so they look their best for display.

Related: How To Make Rocks Look Wet and Shiny

Rock and Mineral Hardness and Composition

The chemical composition of the mineral and its hardness determine which method is feasible for each stone.

The Moh’s scale is something that every rock hunter should be familiar with. It’s critical in almost every facet of the hobby. Even a brush with coarse bristles may severely harm a piece of collected mineral if used for harsher physical cleaning techniques on softer stones.

Just make sure you’re aware of the stone’s hardness. Anything under 5 should not be abrasively cleaned.

And get the most out of specimens, chemical cleaning is required. But, if not done correctly, it can also result in specimens being destroyed.

When it comes to cleaning rocks and minerals with chemicals, silica rocks may be considered inert for the most part. Few substances can dissolve it, making it simple to chemically remove any minerals that have accumulated on the crystals.

Calcium minerals, on the other hand, will often dissolve completely in an acidic environment.

There a plenty of other different reactions that can happen that you should keep in mind. My approach is pretty straightforward:

Before utilizing any chemical cleaning technique on your specimens, always perform your assessment on their chemical makeup.

How To Clean Rocks and Minerals By Hand

For most individuals, just being able to break off the soil around a specimen is sufficient. Stones are more difficult to clean than you may imagine, which can be aggravating. The rock and mineral cleaning methods listed below are effective, and most individuals will use a mix of them to make their pebbles shine.

Soap, Water and a Brush

To begin, use a scrub brush and a little bit of dish soap. You can clean them under running water, like a hose, but I’ve found that a small bucket is typically the most effective way to go.

Note: You should avoid washing stones in your sink. It may not hurt to do it once or twice, but the dirt and sand that falls off your rocks and minerals will accumulate in the pipes. 

Simply make the water nice and soapy and brush as hard as you can. First, use a nylon brush; there are very few stones that may be harmed by a standard nylon scrub brush. I prefer to start with a large brush and then follow up with an old toothbrush to reach the tiny areas afterward.

This will remove the bulk of the dirt on the rock’s surface and loosen any broken pieces, but it’s seldom enough.

Using a Brush and a Probe

Dental probes are ideal for extracting dirt and muck from tiny holes and pockets in your rock and mineral specimens. Dirt that you didn’t see on the first pass may be found with a little more attention.

A wire brush may also be used for extremely compressed material. Note the Moh’s hardness of the specimen first though.

Steel, in theory, will not scratch most silica compounds or tougher materials such as corundum. But I would still recommend using a brush with softer brass bristles.

However, with that said, when using brass brushes on extremely soft mineral specimens, you risk scratching the surface and potentially causing additional harm.

Ultrasonic Cleaning Methods

Ultrasonic cleaners are effective in removing debris and even some mineral buildup, but they must be used with caution. They have a terrible reputation in certain groups.

Ultrasonic cleaners work by rapidly vibrating a container of cleaning solution. This causes cavitation bubbles to form in the solution, which take away materials. The tiny bubbles may penetrate into even the most inaccessible crevices and eliminate any impurities on the stone.

They may be difficult to clean mineral specimens due to the same thorough cleaning.

Ultrasonic cleaners should only be used on hard minerals that have no apparent cracks on the inside. Otherwise, the cavitation produced in fissures may cause stones to shatter.

Similarly, porous minerals and organics degrade rapidly in an ultrasonic cleaner. The Gemological Institute of America (GIA) offers some excellent criteria for gemstones that may be applied to rock and mineral specimens.

The most comprehensive mechanical cleaning technique available is ultrasonic cleaning, but it can also the most dangerous to your specimen.


Sandblasting should be reserved exclusively for very hard specimens with a large amount of material to be removed. Because it may easily damage the surface of most minerals, you’ll need to perform additional cleaning before the rock or mineral is ready.

Instead of quartz or garnet sand, use glass beads as your abrasive medium. You’ll do less harm to the outside of your specimen and in many instances, you’ll be able to prevent any damage at all.

Sandblasting rocks and minerals can be pricey, but if you’re routinely cleaning specimens, it’s a handy item to have.

Air Scribes

An air scribe is difficult to beat for big material removal. These little instruments are marketed as metal marking devices. They’re nothing more than a small pneumatic chisel, and if you have an air compressor, they’re cheap.

Air scribes should be used with caution. These tools are basically a tiny jackhammer, and even a slight lapse in concentration may do harm to your specimens.

Air scribes are only used in certain situations, but they are the greatest instrument for removing huge quantities of material to expose the desired specimen.

Spot Cleaning Guns

Spot cleaning guns are used to clean clothes, but a high-pressure water spray is ideal for cleaning up minerals. They’re a little specialized, but they’re not too costly, and they don’t take up much space.

Use them for initial specimen cleaning; they’ll assist you find out what more you need to do to maintain the specimen in good condition. In many instances, this is the only tool you’ll need.

How To Clean Rocks and Minerals With Chemicals

Before we continue though, I strongly urge you to use extreme caution while utilizing chemicals to clean your specimens.

Some of the substances utilized may cause severe harm to you or others if handled incorrectly. If you’re not sure you can utilize these techniques properly, you should skip them.

While there are certain methods for particular minerals, chemical cleaning is most often used with silica-based stones such as jasper, agate, and quartz variations. This is due to the fact that they are inert to most acids.

If you’re cleaning calcite or flourite, the following will indeed ruin your specimen. Before cleaning a mineral, always do your homework. Some stones may be harmed by even common home cleansers.

Safety First!

To begin, you’ll need the following items on hand:

  • Rubber Gloves: Even a little splash can cause major discomfort, so invest in a well-fitting pair of rubber gloves to avoid injury.
  • Safety Goggles: Instead of eyeglasses, you need goggles that completely enclose your face and eyes.
  • Respirator: When dealing with substances like muriatic acid, even if you’re doing it outdoors, I strongly advise wearing a respirator.

It’s important that you always make sure you have something on hand to neutralize any acids. A large bag of baking soda is the simplest to get. You’ll use it to neutralize any spilled acid before cleaning it up.

Always have safety precautions in place. If you’re not prepared in advance, a spilt bucket of chemicals may be disastrous.

Similarly, chemical cleaning should always be done outside or in a well-ventilated area. While there are certain dangers, you may use a variety of chemical cleaning methods at home. But if you’re prepared to go through with it, the final quality of certain specimens may be much enhanced.

Cleaning Rocks And Minerals With Vingar

If you’re wary of employing chemicals, you may still wipe out a lot of calcium build-up and other readily removable minerals using a gentler approach.

Allow the specimens to soak in vinegar for several days. Because you’ll be cleaning up a quartz crystal or other silica mineral most of the time using this technique, a brass brush may be used to remove stray minerals.

Vinegar may take a few days to completely work. The diluted acetic acid still destroys calcium, but not as strongly as other acids; the primary reason to use vinegar to clean crystals is because it is considerably safer than most other cleaning techniques.

This is a technique you might want to consider when cleaning geodes.

Cleaning Rocks and Minerals With Muriatic Acid

Muriatic acid is a masonry cleaning agent that excels in removing stains from bricks and stone.

It may also quickly degrade less desirable minerals found in your specimen. The bulk of the time, they are calcium-based minerals, which often exhibit unappealing growths on the remainder of the crystal. On one agate nodule, others may create a deep-pocketed limestone matrix.

Here’s the breakdown on how to clean rocks and minerals with muriatic acid:

  1. Using your chosen technique, clean your specimens of surface debris and loose matrix.
  2. Before storing your crystals or nodules in a plastic or glass container, thoroughly dry them. When dealing with acids, avoid using metal containers. The ideal material is Pyrex, although it is not necessary.
  3. Cover the specimens with muriatic acid, being careful not to let any fumes or spills escape.
  4. Check your stones; the calcium minerals will dissolve, so you won’t need to do anything more to get rid of them.
  5. When the specimens seem clean, remove them with latex gloves or tongs and rinse them with a hose. Flush any acids from each sample for 30 seconds to 1 minute.
  6. Prepare a baking soda and water solution and soak the stones in it overnight to neutralize any remaining acids in cracks or seams.

How To Dispose of Muriatic Acid Afterwards

In most cases, disposing of the acid is simple. The instructions are simple: the acid must be diluted to 5% or less or fully neutralized before being poured down the drain.

Keep in mind that you should always add acid to water, not the other way around. So, if you’re diluting the acid by 10x with water, you should add the acid to the water. If you do it the opposite way around, you will produce heat and create a potentially hazardous scenario.

Alternatively, you may add baking soda until the solution stops fizzing. To prevent any heat issues, do this gradually, but after the acid has ceased fizzing, it is largely inert and may be disposed of down the toilet.

I prefer neutralization rather than pure dilution, although both are allowed under Federal regulations. If you’re uncertain, check state legislation, since other jurisdictions may have more severe restrictions.

Using Naval Jelly To Fight Ferrous Oxide

It’s typical to come across quartz crystal formations with a persistent orange colored tint to it. Most of the time this orange coloration is caused by the development of rust owing to the presence of trace quantities of iron in the mineral.

In certain instances, crystals may produce a thin coating of iron oxide. This is most common in quartz or amethyst deposits, however removing the coating significantly enhances the specimen.

Most anti-iron cleansers will work on it. Naval Jelly is a popular choice, and it works just as well on stones as it does on ship hulls.

If you’re wary about using chemicals to clean rocks and minerals, it’s not a terrible way to go before going straight to harsher chemicals.

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