Rock Polishing

If you ever take a look at different precious stones in their just mined form, you would never believe that these stones could look as beautiful as they do when they are ultimately set in jewelry. The credit for making a gemstone look as attractive as it does goes completely to a technique that is known as rock polishing. In simple terms, this is the method by which you can polish and smoothen rough stones to produce more attractive rocks. While traditionally polishing by hand was the preferred method for this process, today the more widely used process for polishing rocks is known as tumbling.

So how do you go about this process of tumbling? Well, the equipment used is known as a tumbler which is made up of an electric motor, a frame with rollers which is connected to the motor with a pulley and a belt, and a barrel. The rocks that have to be polished are put into the barrel. Then water and silicon carbide is added to the barrel. The process is such that the rocks are tumbled with fine grits in order to achieve rocks of the desired shape. The same process also results in the shine on the rocks. A machine is very easy to operate and is easily available at hardware stores. So in case you collect rocks or work with jewelry made of gemstones, you can use these rock polishing machines on your precious stones.

Rock Polishing Instructions

Polishing rocks can not only ensure that your collection of rocks looks much more attractive but also is a way of maintaining them. The supplies you use should include using abrasives that will help you get the smoothness you want in your rock. The entire process of tumbling can be time consuming occasionally taking up to six weeks. All you need in order to start the process is a rock tumbler, your rock collection and grits (silicon carbide) of two types; the coarse variety (60/90 grit) and the medium variety (120/220 grit). Always ensure that the place where you keep your rock tumbler is a dry place and that the tumbler is not exposed to extreme temperatures as that may affect the motor of the tumbler. Select the rocks you want to polish and sort them according to varying degrees of hardness. You could consult the Moh's hardness scale for this. Rocks that have the same hardness will not break if they are grinding together. Do not put in several small or several large stones together. Fill the barrel with stones of all sizes. Before putting in the stones into the barrel, ensure that you clean them once. The barrel should be about two-thirds to three-fourths full and the rest of the space between the rocks can be occupied by plastic pellets. Before you place the rocks in the barrels, measure the combined weight. The measurement of coarse grit that you put into the tumbler will be in accordance to the weight of the rocks. Next you will need to add water which should reach a level that is just a little below the top layer of rocks. Seal the barrel before you start the tumbler and check for any leaks. It is important that you check the rocks daily and remove any rocks that are chipped. After 10 days remove all the rocks and clean them and the barrel properly. Now return the rocks to the barrel but this time the grit to be added should be the medium coarse grit. Again let the process of tumbling and polishing continue for ten days. This process should be continued using finer quality of grit every time till you achieve the desired smoothness and shine. The finer the grit, the harder it will be to clean the rocks after the process of polishing. This is important to keep in mind.

There are several varieties of polishing tumblers available in the market. Depending on your need and usage you can opt to buy a tumbler. The price range of rock tumblers varies between USD 20, for a child's model that can be used to introduce the art of rock polishing to children, to USD 700 for a tumbler that is to be used for industrial purposes. Once the rocks are polished well, you can use them in jewelry of different kinds or even create display pieces.