Basic "How to" Tutorial On Cutting And Polishing A Gemstone Cabochon

Hi everyone, thanks for tuning in. Today I'm going to be showing you a simple video on how to cut a basic cabochon. We're going to be cutting some Australian material, some maramamba tiger's eye. Located in the northeastern corner of Western Australia, the maramamba formation is an iron-rich geological unit in the Archaean Paleoprotozoic Hammersley group. Tiger's eye is recognised as a pseudomorph of chrysidolite, formed by the silica replacement of its crystal fibres. In the case of maramamba material, the replacement is only partial, giving it a beautiful multi-tone effect. Selecting a nice slab, I've decided to cut a square cabochon to really show off the patterning. Using a straight edge, lines to saw the piece are marked. You don't need to be too careful at this point, as any slight problems with the angles can be fixed later. I'm using a standard 6-inch diamond blade saw for this. A splash guard can also be handy to keep the spray off your face. Now that the stone has been trimmed down to its approximate shape, we can start the capping process. The first step is to dop the stone. All you need is a piece of doweling around 5-6 inches long and wide enough to fit your stone, while leaving enough space from the edge of the stone that you won't end up grinding the wood. I am using an electric wax heater, which you can pick up for around $15-20, but a lot of people will use an oil lamp to heat a metal container containing the doping wax. Once the wax is soft, dip your dop stick in and take out a small amount of wax. Then, quickly place it on the bottom of the warmed stone and make sure it is sitting flat against the underside. Now, leave it to cool on a flat surface. From here, we move to the wheels. This is a 6-wheel arbor with 2 metal diamond wheels and 4 soft wheels, ranging from 80 grit all the way up to 3000. It also has an electric pump for its water supply, which is vital for capping or cutting any gemstones. I start off on the coarsest grit and fix up each side to make sure they are all square. I also make sure to take a little off each bottom edge. This is to prevent the chipping often associated with a sharply edged base. You must remember to give your stone a good clean in between wheels. This is so you don't contaminate the fine wheels with a coarse grit. These first two coarse wheels will give the piece its basic shape. As you can see, while wet, the stone is looking good, but after drying you can see that there is a lot of polishing to go now that we have preformed the piece. Moving on to the soft diamond wheels which start at 320 grit, we move up to 600, then 1200, and finally 3000 grit. What is handy to remember with a square or rectangular cabochon is that as long as you polish along each side of the shape equally, you should finish up with a nice symmetrical stone. Though this looks pretty good, the final step for many stones is buffing with a compound like cerium oxide. This will give it that top quality shine. This stage is done with the soft fabric end pad for the arbor. Just take a small amount of the powder and mix it with water to make a light slurry. This can be applied to the stone and the end pad. You should also be keeping the polishing pad damp during this entire process. Give the piece a good buff, making sure to do the sides and the bottom edges as well. Now to remove the dopstick. Simply re-warm the stone until the wax softens and separate the two pieces. Any wax that remains can easily be removed with a scalpel or stanley blade while the wax is still warm. Though not entirely necessary, you may want to polish the underside of the cab as well. I am just doing this by hand, but if you really want a good finish, you can re-dop the stone from the other side and go through the whole process again with care. Now that we have finished the polishing, it's time to clean up the stone. Because I took a bit less care with the base, you can see some of the polishing compound is stuck in small pits. This is where an ultrasonic cleaner comes in handy. It will easily take out the majority of any debris caught in the small pits and cracks. If you don't have an ultrasonic cleaner, then a soft toothbrush and some warm soapy water will also do the trick. And so here we have the finished piece. This may take you a little longer when you first start out, but as you get used to the procedure, a piece like this might take you less than 15 minutes from start to finish. Well, there you have it. I hope you enjoyed this little tutorial on the basics of how to cut a gemstone cabochon. If you did, please hit the like button below, or better yet, hit the subscribe button. I will be putting out a lot more videos like this, not just on how to cut gemstones, but also on gemology, basic field gemology, prospecting, and I'll also be continuing on my documentary series on the mine-to-market trail throughout the world. And remember, it's a lot of fun trying to build up a gemstone collection. You're never going to quite complete it, but it's going to be a lot of fun trying.