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Despite the appearance of specimens in stores and museums, rocks are rather rugged and dusty when they are initially collected from sites. They lack the luster and sheen sought after by enthusiasts, and there are many phases that each rock will go through before transforming into a glistening gemstone flaunting all of its unique attributes. All of these processes will start off with thorough cleaning.
Oxalic Acid is great for cleaning rocks and minerals, and other solutions involving Baking Soda, Vinegar, Hydrogen Peroxide, and Hydrochloric/Muriatic Acid are also effective depending on the specimen and other conditions. Safety precautions should always be taken. (Amazon links)
Many individuals find this to be an absolutely captivating activity, which bestows fanatics with the reward of jaw-dropping before and after results. Whether you’re hoping to clean up a lucky find, or have collected a diverse batch of stones for rock tumbling, we’ve gathered some simple and effective methods for cleaning rocks and minerals so you can establish a great starting point right at home.
If you are interested in checking out the acid for cleaning rocks and minerals only you can find them by clicking here (Amazon link).
What is the Best Way to Clean Rocks?
The word ‘acid’ can be daunting, but there are many household acids or concocted solutions which are relatively safe to use with protective measures and appropriate steps.
All of these solutions work in various ways and to different degrees of effectiveness, with oxalic acid being incredibly effective and offering versatile usability, and other methods being more suitable for differing purposes.
Cleaning Rocks with Oxalic Acid
The oxalic acid powder is quite easy to find, as it can commonly be purchased in one-pound boxes at a local hardware store or at paint shops due to its frequent use.
It may be known as ‘wood bleach’ as well, but just ensure that it is indeed the same thing with a store assistant before purchase.
Using Oxalic Acid is one of the best ways to clean rocks and minerals, particularly when paired with an ultrasonic cleanser basin. It is effective in removing iron oxide which causes the brown staining on minerals.
Although this solution is safe for home use, it is highly toxic. Protective measures need to be taken copiously when working with this substance, as it can be absorbed through the skin as well as by means of inhalation, and it builds up inside the organs over time. The solution should not be spilled anywhere, particularly on porcelain, and should be wiped immediately.
For using oxalic acid most efficiently, establish a setup outside or in an area that is well ventilated, since it would be more effective to use heat to speed up the chemical process.
A plastic container should be filled ¾ full with distilled water, after which the oxalic acid crystals should be poured in and it should be heated up to around 110 degrees Fahrenheit by means of a double boiler type setup.
The solution should never be placed directly into a steel basin, and of course, a plastic container cannot be placed directly onto heat, so using a double boiler setup is the best way to achieve the results, and ultrasonic cleanser basins are a great option.
Although the solution can be heated for a faster chemical reaction which can occur in approximately an hour, the solution should never be boiled.
This solution can be reused which is great for cost-efficiency and convenience, but a new batch should be concocted in the same way once the mixture becomes dark.
These should be left in the solution until the staining has completely been removed from the rocks, after which it should be rinsed in clean distilled water to prevent insoluble oxalates from forming, which will leave unsightly yellow stains once the rocks are dry.
They should then be soaked in a 5-gallon bucket for plenty of room, with a hole drilled at the bottom for trickle and drainage.
The best part is that this can all be set up and ready to go, you’re able to add rock specimens as you find them, and it can handle a large load.
For the most effective results, change the water every minute for an hour, every hour for a day, and then every day for an entire month – or, at the very least, change the water as often as you possibly can using this theory as a guide.
Although it may seem extensive, it’s the best method for cleaning rocks overall, as it removes far more than just dirt and grime, allowing for an incredibly beautiful final product with enhanced appeal and minimal flaws.
If you are interested in buying oxalic acid for cleaning rocks and minerals, I recommend you buy this one (Amazon link).
Cleaning Rocks with Baking Soda
Baking soda is a common household item and is a prevalent addition to rock cleaning methods. Although, despite the widespread belief that it plays a role in cleaning, it serves as more of a neutralizer for the acidic solution which is used to clean the rocks.
This is done by dissolving the baking soda in a container with warm water, then soaking the cleaned and rinsed rocks for around 15 minutes, after which it would be washed thoroughly. It can also be paired with vinegar due to its chemical reaction traits.
Cleaning Rocks with Vinegar
Substances such as vinegar as well as citric acid can be used for cleaning or removing metallic brush marks from rock specimens.
Pastes can also be made with vinegar, and they can be used as a scouring solution or brightening certain specimens such as copper.
Vinegar can be used as a soaking solution for cleaning agates, and a mixture can be made using vinegar and baking soda which results in a bubbling reaction to remove loose dirt. But, it’s important to check a small area first, as some specimens such as calcite do not respond well.
If you are interested in buying vinegar for cleaning rocks and minerals, I recommend you buy this one (Amazon link).
Cleaning Rocks with Hydrogen Peroxide
Although this is not as effective or popular, it can be used for cleaning rocks and minerals but is mainly more effective at removing oxidized material.
Coupled with the fact that it’s an explosive substance when used at an incorrect dilution, and is incredibly dangerous for the skin and other extremities possibly causing blindness or burning.
It’s really not recommended to have a DIY approach with such a substance unless you’re experienced. Potassium Hydroxide may be an alternative for minerals like opal, copper carbonates, and phosphates, as it’s not explosive.
If you are interested in buying hydrogen peroxide for cleaning rocks and minerals, I recommend you buy this one (Amazon link).
TIP: It is always good to clean rocks and minerals before you start to tumble them. But do you know what rocks are the best for tumbling? Find out them in the article below:
Cleaning Rocks with Muriatic Acid
Muriatic acid may be otherwise known as hydrochloric acid and is available for purchase at a wide range of hardware stores. They can be purchased in one-gallon containers, and are effective for removing rust and debris.
Although this substance may be more effective than oxalic acid, this is a rather aggressive approach and this substance is quite dangerous.
Wearing protective measures is essential for working with this acid, and you should always read the safety precautions on the packaging very carefully.
This acid works by not only removing iron oxide stains faster than oxalic acid but removing carbonates such as calcite which often form in pockets last and end up concealing the true nature or aesthetic of the specimen.
It’s commonly used for cleaning many rocks and minerals professionally and produces stunningly magnificent final products.
However, the main reason why this is not the ‘best method comes down to the fact that it’s quite dangerous, as well as the fact that one may hope to maintain calcites in a specimen, and using this acid does not give you that option.
It will remove everything. In addition, this solution can exhaust quickly and is not as reusable as oxalic acid, so it’s essential to keep sand and dirt out of this mixture.
The rocks should be placed in a large container that has room for bubbling foam, they should be washed thoroughly, dried outdoors, and covered with the acid without splashing anything. Muriatic acid acts very quickly, and it should be checked often.
The rocks can be left in the solution for 5 minutes – 5 days, and the removal of calcites will occur much more quickly than the removal of iron oxide.
A second treatment may be necessary by diluting the acid, adding 1 part acid to 1 part water in that order, and it shouldn’t be placed under lighting as it may cause yellow staining.
If you are interested in buying muriatic acid for cleaning rocks and minerals, I recommend you buy this one (Amazon link).
Safety Precautions for Cleaning Rocks
Although there are many ways to clean specimens that are quite safe for home use, it’s still necessary to take effective protective solutions when working with any of these products.
This would entail wearing protective goggles to protect the eyes from debris or fumes, a mask for avoiding the inhalation of any substance, as well as gloves coupled with all-covering old garments to shelter you from the solutions used, which can be harmful to uncovered skin.
Everything should be labeled for safety and should be kept far away from animals, children, and others in the area.
Plastic containers and colanders should be used for each of these methods, and it’s important to examine the specific rock or mineral with the solution by testing the substance on a small area of a rock in order to see what the chemical reaction will be before going ahead with a full batch.
TIP: If you are looking for some protective gloves for cleaning rocks or even for rockhounding? I wrote a comprehensive article about gest gloves for rockhounding, feel free to read it here:
There are plenty of ways to clean rocks in the comfort of your home, using acids that are easy to find at local hardware stores.
However, the compatibility of the rocks with each method will vary depending on their form and composition, and it’s always essential to check a small area before deciding on an appropriate method.
Safety precautions and appropriate conditions of the environment should always be ensured before working with such substances.
With some thorough knowledge of chemical reactions and classic elbow grease, you will be all set for creating a glistening collection of rock and mineral specimens.
TIP: Sometimes it happens that your rock collection is already too big and you don’t know what to do with it. I have some useful ideas for you on what to do with your old rock collection, find out more in the article below: