One of the most tedious parts of rock hounding is cleaning the rocks. It’s not bad when they clean up quickly but sometimes getting the dirt, mud, lichens, moss and stains off the rocks can take what seems to be forever. Below is the process I go thru to clean my rocks.

The first thing I do when I get my rocks home is try to rinse them off with the garden hose. This generally gets the loose dirt of them but sometimes I have to use a nylon brush to get the stubborn dirt of them. Some people use a brass brush at this point. I have not tried to use a brass brush but it does seem to be a very good tool for the job. A brass brush can be purchased at most hardware or paint supply stores. This first step allows me to get an idea of which rocks I want to work with right away.

After using the garden hose I split the rocks into three piles. The first pile is the rocks that are already clean enough to start cutting and polishing. The second pile consists of the rocks I want to work right away but need further cleaning. The remaining rocks get tossed on the rock pile for future cleaning and cutting.

Those rocks that I want to work but need further cleaning then go to a soaking bucket or sometimes the kitchen sink. I soak them in warm water with dish soap, just like I am going to wash dishes. After about thirty minutes of soaking the rocks are once again scrubbed with a nylon brush and rinsed off. If the nylon brush does not remove hard dirt or can’t reach the dirt I use an awl to pick away the dirt. Some people use dental picks to do this. The rocks that still need cleaned are then left soaking and scrubbed time to time until they are clean. Sometimes the soaking will last for a couple of days.

If soaking does not remove the dirt or if rust stains remain on the rocks you can use muriatic acid. Muriatic acid also known as Hydrochloric acid can be found in most hardware stores. When working with acid do it outside in a well ventilated area. Precautions must be taken because using muriatic acid it is dangerous. Always wear gloves and eye protection. Do not inhale the fumes or get it on your skin or in your eyes. Be sure to read all warnings and handling direction on the bottle.

The first thing I do when setting up is to dilute the acid. In a five gallon bucket I add 1 part acid to 20 parts water. Always add the acid to the water, not water to the acid. Remember to leave room in the bucket for the rock. I try to only mix enough acid solution to cover the rock. The acid can be reused and will get dark in color over time. If the acid is to dark to see the rock it should be deposed of. The acid can be neutralized using lime or baking soda. Many communities have programs where toxic chemicals can be dropped off; this is the best way to get rid of the used acid.

Next I gently place a test rock in the acid solution. Be very careful at this point because it is easy to cause the solution to splash. If the test rock is not damaged after fifteen minutes I put the rock I want to clean in the solution. I leave the rock in the bucket for fifteen minutes to a couple of days depending on how well the dirt or stains come off.

Once the rock is finished soaking in the acid solution it needs to be soaked in water and baking soda to neutralize the acid. Leave the rock in the soda water for three times the amount of time soaked in the acid solution. Changing the soda water often can make the neutralization process more effective.

After the rock is finished soaking in the soda water I once again clean the rock with water and dish soap before cutting and polishing.

There are other ways to clean rocks than the way I do it. If you have a technique that works well for you please share it with me via the form on the contact page. I will be glad to update this writing with your information. Credit for submitting the information will also be listed.

Two weeks ago I wrote about a possible fieldtrip to Hog Creek and doubted that it would take place due to the weather. The night before it stopped raining and by morning things were still damp but not enough to stop the trip. We left Caldwell, Idaho at around 8:30 and by 10:00 we were at Hog Creek near Weiser, Idaho. The road into the collecting site was a bit muddy going in but dry by the time we left.

When first arriving at the collecting site I started to dig for agate nodules and found mostly fragments and lots of crystal pieces. After digging for about two hours I had about a gallon of pieces I thought had some potential. At that point I gave up digging and wondered around for a while to see what could be found on the surface. I found another gallon of small intact nodules but still didn’t feel that excited about them. I finished the day by digging around a little bit more and exploring a few other areas. By the end I finally had a bucket full of rocks but was not sure I had anything good.

When I got home I picked out some of the intact nodules and cut them in half. I was surprised to find wonderful blue agate centers. The nodules polished up very well. The next morning I took some of the broken pieces I had collected and cleaned them up a bit. There were a few really nice items that I cut and polished. Some of the crystal pieces were given to the neighbor kids that like to come over and watch me work on my rocks. The hall from Hog Creak may have been small but it yielded some very nice pieces.