Collecting stones is a fun hobby for adults and children; it's inexpensive and a great excuse to spend time outdoors enjoying nature. If you have small children, this is also an opportunity to teach them some science. Once you have collected many soft stones, you can polish them to bring out their natural colors. The concept behind this process is simple: just like it happens in nature, you have to rub a harder stone (in your case sandpaper or abrasive powder) on a softer stone to remove the surface layer. No special tools or sifter is needed to polish the stones by hand and make them beautiful.
Steps
Part 1 of 3: Collect the Polishing Stones
Step 1. Get them in person or online
You can go to natural environments and find the ones that interest you; look for small pieces (as large as an inch), not grainy (sandstone is never a good choice) and that do not have fractures or cracks. You should also avoid stones with many small irregularities on the surface, as they do not polish well.
- If you are starting this job for the first time, you may have a hard time finding good quality stones on your own. Get in touch with a group of experienced collectors and ask them for some advice on where to find stones to polish.
- There are many websites that provide information and help on where to collect the stones; there are just as many that sell rough and unpolished pieces, even in large quantities.
Step 2. Find some stones you would like to polish
You should start with the softer ones, as they are easier to shape and handle, as well as requiring less time and effort. Soft stones include: onyx, calcite, limestone, dolomite and fluorite.
The stones are classified by hardness thanks to the "Mohs scale" which goes from 1 (very soft mineral) to 10 (very hard mineral). Most of the stones mentioned above have a grade 3-4 on the Mohs scale
Step 3. Scrape the stone with the tip of a small knife
This way you can tell if it is hard enough to be polished. If the scratch is white or wrinkled, the material is too soft - you can polish it, but it won't look any better.
- If there is a metallic mark left by the knife blade, the stone is hard enough to work with.
- Be careful when using the knife and always scrape the stone by moving the blade away from your body. It doesn't take a lot of pressure, start with little force and gradually increase it as needed.
Step 4. Shape the stone using a hammer and chisel
Often, the stones have a strange or irregular shape; to try to make them rounded and symmetrical, use a chisel and a hammer. In particular, if you plan to polish large stones, you should break away any bumps that are too large.
- As rock dust is dangerous for the lungs and eyes, it is recommended to wear safety glasses and a mask during this work.
- When you have shaped the stone according to your wishes, get rid of the rough edges by rubbing them on a concrete surface.
Step 5. Eliminate all dirt and debris on the stones
You can simply put the stones in a bucket of hot soapy water and let them soak for half an hour; in this way, you soften all the foreign material that has remained attached.
- Once you have washed the stones, rinse them off.
- It is important to remove excess earth before polishing them, otherwise the sandpaper or the sifter will get dirty and not effective.
Step 6. Choose the stone you want to polish first
You should opt for the smaller and softer one during your first polishing attempts, as it allows you to do a quicker and easier job.
When you see the final result, you are motivated to continue in this pastime
Part 2 of 3: Polishing the Stones by Hand
Step 1. Take the 60 grit sandpaper and rub it on the stone
This is a rough, coarse-grained type of paper that does not polish the soft material at first, but shapes it slightly. If you want to get a rounded stone, start working it on the corners and smooth them evenly. When the stone reaches the shape you want, you can move on to finer-grained sheets.
- Periodically dip the stone in a bucket of water to keep it wet.
- 60-, 160-, and 360-grit sandpaper should be available in hardware stores.
Step 2. Dip the stone into the water again
Switch to 160-grit emery paper and rub it over the scratches left by the rougher one. You may notice that this paper leaves some scratches on the surface, but makes large ones even.
Remember to keep the stone wet; dip it from time to time into the bucket of water. When you've removed the larger incisions, proceed to the next step
Step 3. Take the 360 grit sandpaper and continue sanding the stone
Just like you did before, you need to work the surface to make it even smoother and more even. The finer sheets of emery paper remove the imprinted marks from the rougher ones, leaving only very small scratches.
- Continue rinsing the stone on a regular basis; it is important that the surface is wet when you sand it.
- The process is completed when all the scratches left by the previous sanding are smoothed out.
Step 4. Polish the stone with a sifter
If you don't have the time or desire to polish the stones by hand, you can use this tool that uses the same principle: instead of sandpaper you have to add abrasive sand to the cylinder along with the stones.
Although using the tumbler requires less physical work than manual polishing, it does take a long time. You have to insert the stones into the cylinder for three cycles (with increasingly fine abrasive material) and each session lasts 7 days. The final polishing process takes one week
Part 3 of 3: Finishing the Stones
Step 1. Apply the abrasive powder to a wet denim cloth
Start polishing the stone until you get the result you want. This operation removes all the scratches left by the finer-grained sandpaper and gives the stone a brilliant shine.
- You don't have to put a lot of dust on the cloth; it is best to start with a small dose (half a teaspoon) and then add more, only if necessary.
- The abrasive powder for polishing stones is available in hardware stores. Typically used with tools such as the Dremel; if you are having difficulty finding this substance, ask the shop assistant if he has such a tool in stock.
- If not, you need to go to a craft or gemstone store to find the powder.
- Remember that colored powder can sometimes alter the natural color of the stone.
Step 2. Polish the stone with a strip of leather
You can do this after using denim fabric and abrasive powder or as an alternative method. The leather gives an even shine and makes the material smooth and soft to the touch.
You can add abrasive powder to the leather cloth to smooth and polish the stone in a single session
Step 3. Apply a finishing product
Typically, jewelers use it to put the finishing touches on their creations, but it can also be used on polished stones. Put some on the denim cloth or leather strip you used earlier and smear it on the stone.
- Know that this is an optional step. These finishing products are often colored and alter the hue of the stone; if you decide to use them anyway, choose one that matches the natural color of the stone.
- If you have trouble finding this substance in hardware stores, do some research at a gemstone or craft store. as a last resort, consult a jeweler.
Advice
- Start polishing small stones; when you have become familiar and mastered the technique, you can move on to those of greater size and hardness (if you wish).
- Don't use too much abrasive powder, just a little.
