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Share With Other Rockhounds! If you’re thinking of starting a new hobby and have a knack for collecting pretty stones, why not try out lapidary? Lapidary is the art of shaping, cutting, and making jewelry out of semiprecious or precious gemstones. Dealing with gemstones involves a lot of tools, so before dipping your toes into lapidary waters, you need to be familiar with the needed equipment. We prepared a guide of the best lapidary equipment for beginners, as well as all necessary accessories and tools. Related: Where To Buy Used Lapidary Equipment Lapidary Equipment for Beginners (The Essentials) Just like any other hobby, having a designated space for the tools and equipment will help you stay organized, and enjoy your time. Most of the equipment is loud, so make sure to pick a place where the noise won’t bother your neighbors. Read more on how to make a rock tumbler quieter here. 1. Organization – A Place to Put Everything Setting up a workbench (or a couple) for your tools should be your first step. It doesn’t have to be a fancy workbench, you just need a sturdy table, preferably with drawers to keep your small tools in and a large surface area. As your precious rocks collection grows, you might want to invest in divided containers to keep matching rocks together, and away from other harsh stones and crystals. 2. Trim Saw or Slab Saws Not all rocks and gemstones are sized equally, so when it comes to cutting your rock collection, there are two types of saws you’ll need; a trim saw and a slab saw. A trim saw has a small, thin blade, that is made for cutting small stones into smaller chunks, or for creating a flat edge for a cabochon. Hi-Tech’s Diamond Trim Saw is a good starter option. A slab saw has a larger and thicker blade, making it suitable for trimming down rough rock slabs, or large stones that won’t fit into a trim saw. This slab saw option has a vise to help you trim the rock safely. 3. Rock Tumblers A tumbler is one of the must-have equipment in your workshop. There are two types of tumblers: rotary and vibratory, but both serve the same purpose of polishing and rounding rough stones. Rotary tumblers are barrel-shaped and rotate slowly to polish the rocks inside with the help of other rocks and abrasives. We recommend getting a single barrel beginner-friendly tumbler like Lortone 3A Single Barrel Tumbler. Vibratory tumblers (or vibes for short) take much less time to polish up stones and maintain the original stones’ shape. Vibes have a container that shakes the rocks rapidly, the shaking causes friction which in turn polishes the rocks. If you’re interested in trying out a vibe, Raytech’s Vibratory Tumbler is a good start. Tumbling Filler When working with a small number of rocks that don’t fill up your tumbler’s barrel, you’ll need to use filler. You can use ceramic fillers or plastic fillers, both provide cushioning and extra polish to your stones, without damaging them. This kit here has enough filler and grit for the 4 stages of your tumbler. 4. Cabbing or Cabochon Cutters If you’re opting for rounded cabochons fit for pendants and accessories, then you’ll need a cabbing machine. Cabbing machines consist of a station that has one or multiple grinding wheels with different grits. Some may even come equipped with a saw to make the cabbing process easier by giving stones a flat back. However, you can always get a machine with one grinder wheel and have a belt for each cycle. You’ll mainly need grinding belts and a polishing belt. Machines with multiple grinding wheels can be a bit pricey for beginners, so we recommend getting a simple slanted cabbing machine. 5. Faceting Machines These machines consist of a mechanical arm, lap, and a water cooling system. The mechanical arm is where you fasten your gem and adjust its angle according to which type of cut you’re going for. The lap is a disc that can be changed out according to which grit you need and is kept cool using a water drip system. This option by TBVECHI is a good option for beginners, however, it doesn’t come with a drip system, but you can easily work around this by using a wet sponge on the lap disc before faceting. If you want to cut down on equipment costs, you can use a faceting machine to make cabochons. However, you can’t use a cabbing machine to make facets. 6. Flat Laps These are the budget-friendly alternatives to faceting machines, and some people even make flat laps at home. A flat lap is a grinding disc on top of a spindle, usually with a setup water drip system. Laps can be ergonomic to make the grinding process easier, or horizontal. The grinding discs have different levels of abrasiveness for each phase of faceting. A coarse disc is used for the initial shaping, which is swapped out later on for a finer-grit disc for polishing. Some discs are available in a magnetic form to be easily swapped out. However, we don’t recommend using magnetic discs at high speed as they could fly-off. A good option for a flat lap is Hi-Tech’s All U Need Machine, which comes with multiple disc options for you to try out. 7. Rotary Tools and Dremels Carving intricate shapes and details onto stones will require a rotary tool or a Dremel. Most models come with different attachments for carving, grinding, and even polishing to touch up your pieces. Rotary tools are perhaps the most flexible of all the tools because the bits and burrs can be easily swapped out. You can opt for a diverse set like the Dremel Rotary Tool Kit, this kit has all the different accessories you could need, along with a handy LED light. 8. Dop Sticks and Wax These are a must-have if you’ll be cabbing or faceting your stones. Dop sticks are essentially wooden sticks with globs of wax on one end. Different Types Of Quartz Crystals [Advertisement] Your video will begin shortly When heated, the wax becomes malleable enough for you to stick your stone’s base to, and once you’re done shaping your stone you can simply heat it again to release the stone. However, you can also use a wooden dowel and wax or 5-minute epoxy to fix the gem in place. They prevent injuries, as well as provide a grip on your stone for easy shaping. We recommend watching a tutorial to understand how they work. Read More: Dop Wax Substitute (No Dop Wax? No Problem) 9. Polishing Tools Even after buffing and polishing your rocks with the different attachments your equipment may have, they might still need an extra step to make them shine bright. Burnishing powder or polishing powder is often used in tumblers to give an extra shine to stones that may be covered with fog or water residue. The amount of burnishing powder will depend on how many stones you have per batch. Some types of stones will only require some buffing with a polishing cloth or even a piece of denim. Buffing and polishing belts, wheels, and bits and burrs are also readily available as accessories for grinders and rotary tools, so make sure to take advantage of them and make those rocks sparkle. Ultimate Guide To Lapidary Polishing Compounds 10. Lapidary Accessories A workstation isn’t complete with the appropriate accessories to help you with making the best out of your gemstones. These a few more additions to your cabinets to make your lapidary experiences a breeze: A colander to wash your stones off before using them A magnifying glass or loupe, also known as jeweler’s eye, is your best friend when examining your collected specimen for damage or patterns. Read my article about the jewelers loupes that I recommend. Cabochon templates, are plastic or metal stencils of different shapes and sizes of cabochons to guide while cabbing and help you create uniform shapes Safety First Dealing with saws, grinders, and stones needs the proper gear to keep you safe and sound, here’s a list of some essentials you’ll need: Safety goggles to avoid any flying shards or stone dust A finger guard or finger guarding tape. These are optional but help with avoiding blisters while cabbing or faceting Safety gloves, this is a must when using any type of saw or drill bits This list is mostly for guidance, but you should follow the full safety regulations while working with power tools. This includes electric, mechanical, occupational, and chemical safety. Keeping your work area well ventilated, properly lighted, and comfortable are also important considerations. Lapidary Books to Get You Started If you’re looking for good books to polish up your knowledge about lapidary, we’ve got you covered with our list of beginner-friendly books and guides. Gemstones and Minerals Identification and Uses Collecting Rocks, Gems and Minerals: Identification, Values and Lapidary Uses We earn a commission if you click this link and make a purchase at no additional cost to you. Curious as to what types of stones are out there? This illustrated guide will help you identify the different stones you collect, as well as what type of technique suits them. If you’re looking for a handbook on all things rocks and minerals, the Smithsonian Handbook: Rocks & Minerals is also a great read. How To’s and Guides Gemstone Tumbling, Cutting, Drilling & Cabochon Making: A Simple Guide to Finishing Rough Stones Join The Rock Seeker Community! - Access the private Rock Seeker Facebook group! - Receive The Rock Seeker Newsletter - Never Miss New Content! - Connect with like-minded rockhounds! SIGN UP NOW! I consent to receiving emails and personalized ads. This https://www.lapidarytool.combook has all the different lapidary techniques covered and provides detailed instructions for each technique. Not only is this suitable for beginners, but it’s good to keep around for any needed memory jogging. The Art of Gem Cutting is a valuable addition to your reading list when starting out. Guiding you through the entire process from buying the stones to the final polish. The Art of Gem Cutting: Including Cabochons, Faceting, Spheres, Tumbling, and Special Techniques

by Donald Clark, CSM IMG Missed Index One of the most common faceting mistakes we make is not setting the index correctly on our faceting machines. If you miss it by just one notch, it’s enough to throw off the entire design. Here’s the diagram for a meetpoint oval being cut with a 64 index gear. You should cut the shaded facet at 44.7° and I 7, (followed by I 25, 39, and 57.) Now, say you make a mistake and cut it at I 8. If so, you should cut symmetrical facets all the way around, using indexes 24, 40, and 56. How do you determine that? The Solution Simply add and subtract the proper number from your top and bottom index settings. This index gear has a setting of 64 (or 0) at the top and 32 at the bottom. We started with 8 from the top. Therefore, subtract 8 from 64 and you get 56. Add and subtract 8 from 32, the bottom center, and you get 24 and 40. Your gem will look like this (with the new facets shaded).

Lapidary Equipment for Beginners Whether you are a rockhound, gem and mineral collector, jewelry maker or simply someone who appreciates a beautiful gemstone, you are sure to encounter the field of lapidary. Have you ever wondered how to shape, smooth and polish gemstones or semi precious stones? In a nutshell, that’s what lapidary is. It’s the process of shaping and putting a nice finish on a stone. Although some lapidary processes require high levels of technical skill, expertise and the use of complex equipment, there is almost no barrier to entry for the beginner. Getting started in lapidary does not necessarily require a workshop full of fancy equipment. A lot can be achieved with a minimal amount of tooling. Let’s take a look at some basic lapidary techniques and equipment available to beginners. The fundamental principal of progressing through a series of increasingly finer abrasives applies to all of these processes yet each process employs a unique set of tools and equipment. Polishing stones in a tumbler These colorful stones were shaped and polished using a tumbler. Tumbling can be thought of as a way to mimic nature breaking down stone through erosion. Have you been to a rocky beach or walked through a dry riverbed and observed that the stones in these places are rounded and smooth? These stones have been naturally tumbled smooth. If you have never made this observation, now is a great time to take a hike and go look at some lovely, smooth river rock. Over time, water flowing through the river channel forcefully agitates the stones causing their sharp edges to wear down. The same thing happens on the beach with repetitive pounding of the waves. And this is also what goes on inside the barrel of a tumbler except we get to add a little twist to speed up the smoothing process. By combining the rough gemstones with hard abrasive grit and mechanically shaking or rolling them around in the tumbler we re-create the action of the beach or the river on a human scale instead of waiting for a geologic eternity. One thing the river hasn’t figured out yet is how to polish the rocks after they’ve been tumbled smooth. But we humans are clever and we follow the basic principles of lapidary. We know that by changing out the abrasive periodically to progress through grits from coarse to extremely fine, we can put a polish on those stones high enough to see our own reflection. Tumblers are great for beginners because they are mechanically simple and require virtually no dexterity or finesse. Just load up the tumbler, close the lid and away you go. Depending on the stone material and the type of tumbler used, it can take many weeks to polish start to finish. Patience is a key ingredient for tumbling. But once the tumbler is loaded and started it does all the hard work automatically and you can pay attention to other things. There’s no sound quite like the soothing rumble of a tumbler gently rolling in the background. There are two types of tumblers to choose from, rotary tumblers and vibratory tumblers. Rotary tumblers A rotary tumbler has a cylindrical barrel that rolls horizontally on a drive shaft. It tumbles the rocks inside the same way that clothing gets tumbled in a clothes dryer. Lortone tumblers are easy to use and great for beginners. We now carry a line of rotary tumblers from Covington. Take a look in our shop and you’re sure to find the right model for you. Vibratory tumblers A vibratory tumbler comprises a hopper attached to a vibrating mechanism which rapidly shakes the hopper and it’s contents. This clip shows a LOT-O tumbler in use. Generally, rotary tumblers are better at taking rough stones down to a smoother, more rounded shape. They take longer than vibratory tumblers which work much faster for polishing but are not ideal for achieving rounded shapes. A beginner might start out with a rotary tumbler to get some hands on experience. Then, by adding a vibratory tumbler later they can enjoy the best both tools have to offer. Cabochon cutting on a cabbing machine For some beginners, the patience it takes to wait for a batch of stones to finish tumbling would be agonizing. Fortunately, there are other lapidary activities that take less time. Cabochons can be made of nearly any gemstone material. This is a beautiful example cut from dendritic moss agate. Cabbing machines Within the field of lapidary, cutting and polishing cabochons on a cabbing machine is the ultimate form of instant gratification. A nice cabochon can literally be made in under an hour and a beginner can take to it right away. Demonstration of a cabbing machine at a gem and mineral show Typically, a cabbing machine has an array of six grinding and polishing wheels arranged next to each other on a long shaft. The shaft may be directly attached to a motor or it may be mounted on bearings and attached to a belt and pulley drive. The abrasive surface is on the cylindrical perimeter of the wheels. Each wheel on the shaft employs a different mesh size abrasive and the wheels progress incrementally from coarse for shaping to medium for smoothing to fine and extra fine for polishing. A water drip system or splashing system keeps the wheels wet and a shroud catches water flung from the wheels as they spin. The coarse grinding wheels are often metal with diamond grit either sintered or electroplated to the grinding surface. The fine abrasive wheels are often composite materials with some cushion and the grit is bonded to the grinding/polishing surface with resin. Sometimes a leather disk charged with polishing compound such as cerium oxide is mounted on the end of the machine for a final buffing finish. The 6″ Cabbing available in our shop is a great cabochon machine to get started in cabbing. Watch out, it’s so much fun you may never want to stop! Trim saws This trim saw has been used to cut amber. Some scrap pieces remain on the table which would polish up nicely in a tumbler. Paired nicely with a cabbing machine is a trim saw for cutting out cabochon blanks. Trim saws are small, wet operated diamond saws with a table to support a thin stone slab. The saw blades are usually in the range of 6” to 10” in diameter and are meant to be operated freehand. Learn more about the various types of lapidary saws. With no other tools but a cabbing machine, a trim saw, some dop sticks and dop wax, a beginner can learn how to turn a slab of stone into a finished cabochon in one sitting. And Covington makes a combination unit that includes the saw, grinding and polishing wheels all in one machine. It’s a great way to save space and comes with everything you need to get started. Go for the diamond model. It’s available in our shop. Carving gemstones with a flex shaft tool It takes a lot of talent and practice to carve a fancy intaglio or intricate shapes into a gemstone. However with some persistence, carving basic, free form organic shapes and curves is doable for a beginner. And, this really can be an inexpensive and space saving way to get a start in lapidary. This talented craftsman is carving green jade using a hand-held rotary tool. Flex shaft rotary tools A Foredom flex shaft tool or a Dremel tool with a flex shaft attachment, along with a handful of bits, burrs and a water drip system is the basic set up for lapidary carving. The work should be kept wet while carving to keep the burrs and the stone from overheating and also to prevent generating dust. To keep things wet the work is done under the stream of the drip system or alternatively dipped frequently into water. Carving is done freehand with the flex shaft handle in one hand and the stone in the other. A dop stick attached to the stone can also be helpful for holding on to the work. Coarse shaping happens first with coarse grit diamond burrs followed by smoothing with finer grit burrs. Pre-polishing and polishing is achieved using buffing wheels and shaped felt or wooden bits charged with the appropriate polishing compound. The only limits to the shapes that can be made by carving are from the materials. Some materials are more brittle than others limiting the carver to simpler shapes. Some materials are more forgiving and invite more adventurous designs. A carved animal figurine made of lapis lazuli Cutting and faceting on a flat lap machine A beginner can graduate to more advanced faceting by learning the basics with a flat lap machine (also just called a flat lap) on which simple faceted shapes such as pyramids, cubes and crystal forms can be cut freehand. Cabochons can also be effectively cut and polished on a flat lap. With a little practice, pyramid shapes can be cut freehand using a flat lap. Flat lap machines The grinding and polishing surface of a flat lap is on the planar side of a disc-shaped wheel (called a lap disc or just lap) which rotates on a spindle. Some flat laps are oriented at an angle for ergonomics and others are horizontal like a record player. As with other lapidary equipment, a water drip system keeps the grinding surface wet and a shroud with a catchment system keeps the water contained. This flat lap machine is oriented horizontally. The water drip system is a simple gravity feed controlled with a valve. To progress through the series of abrasives, the coarse lap must be removed from the spindle and changed out for the next finer lap. To save time, some people use a magnetic backed lap disc that grips a steel platen on the machine making it easy to swap them out. The Flat Lap comes in two magnetic versions as well as the original “swap out” version. They are high quality machines and we offer all the models in our shop. Faceting machines Worth mentioning here are faceting machines even though they are more advanced, more expensive and not usually where a beginner would start out. However, some mechanically minded beginners would naturally take to mechanized faceting techniques after learning basic flat lap techniques. Fundamentally, a faceting machine is a flat lap machine that incorporates a mechanical arm with an indexing dop stick holder. This arm, attached to the machine body, accurately guides the gemstone to contact the lapping surface at various angles in relation to the machine platen. Australian gemstone cutter Cliff (Vintage Time) demonstrates how to facet step by step. What makes a faceting machine an option for a beginner? Any manual move that can be made on a flat lap machine can also be done on a faceting machine. It can be operated freehand without using the mechanical arm. In this way, the beginner can learn the basics and then advance without acquiring more equipment.

Polishing and the tools for polishing are a bit like your favourite pair of jeans, you tend to wear them as much as you can and sometimes even buy the same pair. This is very much the case for polishing tools, after trying different materials and tools, in the end you stick with the same tools and materials for years, which never let you down (Unlike those jeans!) Here is an insight into the best tools and materials to start polishing your jewellery. 1. Dremel/Pendant Motor If you don’t have the budget to buy a large bench polisher, then a Dremel or pendant motor is the tool for you. Dremels or pendant motors are a highly versatile tool as they can be used for polishing, engraving or texturing your silver and even stone setting. This tool will not only give you the best start to polishing your jewellery but also let you experiment in other areas. 2. Rubber Burrs Rubber burrs are an unexpected game changer for polishing jewellery. You can use a medium rubber burr for quickly softening sharp edges or an extra fine rubber burr to go over the surface of a piece to help get rid of any scratches. (Think of them as burrs of emery paper which you can use with a Dremel/pendant motor). 3. Emery Paper Emery paper is a great tool for jewellers and is often used for the first stage of polishing. Working from Grade 500, 1200 and then 2000 creates a scratch free surface, simply rub your piece onto the emery paper with some pressure 4. Mop Heads Mop heads can be multifunctional, both polishing your pieces and saving you extra work later in the process. For example a Calico mop head is great for giving a perfect polish but is also the best mop head to use to quickly get rid of stubborn fire scale and if paired with a leather mop head any light scratches left on the piece will buff out really well all while keeping the shine! 5. Rouges Rouges can be your best friend and enemy at the same time, for example Luxi Red Rouge makes for a messy work space but can be forgiven as the shine it gives the silver is perfection. However, Luxi Blueis much better at getting rid of fire scale, much cleaner and also lasts much longer, also very little dust is produced and pieces polish a lot quicker with Luxi Blue. 6. Polish Cloths The final stage of polishing comes when you buff up your pieces and see it come to life in the polish cloth. Two separate cloths are ideal- the first plain cloth to get rid of any excess rouge and a second polishing cloth to use before the pieces go into their box for one last buff. Hopefully you found out about some tools and materials which could help you on your polishing journey!

If you’re new to the jewellery making crowd, you may have come across the term – but what is lapidary? Putting it simply, lapidary is the art of working with gemstones. There are many different ways that lapidarists work, but one of the most rewarding ways is to make jewellery with gemstones. Either as a pendant or as a setting in a ring or bracelet, there are a variety of different ways you can incorporate lapidary work into your projects. Find out more about the various techniques and lapidary tools below. What are the different arts and techniques of lapidary? So, what are the different arts and techniques of lapidary? The main three are: tumbling, cutting and faceting. To help you understand what each means, we’ll talk you through the processes involved and the outcome of each technique. Tumbling Just starting out? This technique could be for you. Requiring the least equipment and minimal effort, tumbling is a great place to begin your lapidary journey. Simply place any rough gemstones you have into a tumbling machine, use for the required amount of time and your gemstones will emerge polished. So remember to keep an eye out for any gemstones the next time you’re at the coast – as these can make beautiful jewellery pieces! Top Tip: Make sure you check whether or not the stones you’re working with are suitable for tumbling as some softer stones could be scratched or damaged by the tumbling process. Cabochon Cutting Also known as ‘cabbing’, cabochon cutting is one of the most common forms of lapidary art. Taking slightly longer to master, this technique is used to enhance and display the natural pattern of a gemstone that may otherwise be hidden. Cabochon cutting is usually used on softer stones where faceting wouldn’t be suitable. If you’d like to find out more about this technique, read our what is a cabochon cut gemstone blog. Faceting And the last in our lapidary techniques list is faceting. If you haven’t heard of this before, faceting is where a gem has a number of flat surfaces, or facets, in order to reflect the light entering the stone. Most jewellery makers use a faceting machine to create this effect. Commonly used on diamonds in wedding and engagement rings, faceting is one of the most profitable lapidary techniques. Lapidary tools and equipment Interested in giving one or more of these techniques a go? You’ll need to pick up a few key pieces of equipment first. The basic lapidary supplies for beginners include: Gemstones or rock slabs. Depending on whether you want to start from scratch or not. Burnishing powder. To give your stones that extra shine once they’ve been polished. Silicon carbide. In a similar way, silicone carbide is great for making your stones super smooth and free from coarse scratches. Safety glasses. If you’re sawing any of your rock slabs or cutting gemstones, always remember to wear safety glasses. A trim saw or slab saw. For smaller rock slabs, use a trim saw and a slab saw for larger pieces. A colander. If you’re planning on tumbling your stones, you’ll need a colander to rinse them through once the process is complete.

Cabochon cutting or cabbing is the most popular form of gem cutting. Although it requires a fair amount of skill, almost anyone can master this technique. Rough material for cabbing can be found or purchased inexpensively. Many people never buy their rough and are content to cut the many stones they trade for or find. Of course, as you gain experience, you can if you wish move on to more valuable materials like turquoise, lapis lazuli, and even phenomenal stones like cat’s eye chrysoberyl and black opal.BY DONALD CLARK, CSM IMG Cabochon cutting is challenging, but with patience and practice, anyone can learn the most popular branch of the lapidary arts. Rhodochrosite and gold ring, photo and jewelry by Mauro Cateb. Licensed under CC By 2.0. Cabochon Cutting Tools Cabbing tools can be as simple and inexpensive or elaborate and pricey as your tastes run. Genie, Diamond Pacific The most popular cabochon cutting machine is the Genie by Diamond Pacific. It has six permanently mounted wheels. The first two are 100 and 260 grit diamond on solid wheels. The other four range from 280 to 14,000 grit. They have a foam backing, which conforms to the curvature of the stones. There are two movable “geysers” that supply water to the wheels for lubrication. You can’t polish everything with one method, so this machine comes with a flat disk you can mount on the end. This disk can hold enough varieties of pads and polishing compounds to polish anything you might encounter. The Genie’s advantages are that you never spend time changing accessories and that the diamond wheels last almost forever. Cost is its primary disadvantage. This machine is a major investment. It’s also large and heavy, which is fine for a permanent setup. However, if you need portability, this isn’t the unit for you. More Options There are a number of cabochon cutting machines available with a variety of features and prices. Some people have made their own machines. The requirements are: an axle of the proper diameter for the wheels you want, a motor, a pulley system to attain the proper speed, and a method to keep the wheels wet. This is usually a drip system. For a simple solution, place a sponge so it sits in water and constantly wipe the wheel clean. You can cab on a faceting machine, but you can’t facet on a cabbing machine. If you’re a beginning lapidary student and budgeting your equipment costs, keep this in mind. You can shape your cabs with the same coarse laps you use for faceting. Clean your coarse lap, then put a piece of firm, 1/4″ thick, foam rubber on top of it. This will hold pieces of 600 grit wet/dry sandpaper (that you must cut to shape) for smoothing. To polish, replace the sandpaper with an Ultra Lap, a piece of leather, or other polishing pad charged with your favorite compound. Cabochon Cutting Techniques The oval cabochon is the most common shape for cabs. Other shapes just require minor technique adjustments. In this section, you’ll learn how to cut an oval. Slabbing Cabochon cutting template Most cutting begins with a slab. Yes, that means you’ll need a saw. Some cabs can be cut without slabbing, but most will need to be cut into 1/4″ to 3/8″ thick slices. Begin by placing a template over the slab. If your material is a solid color, you’re just looking for the largest piece you can cut. If the material has a pattern, then you’re looking for the shape and size with the most eye appeal. This is a bit of a guessing game, since the pattern will change as you round the top. Look at both sides of the slab to get an idea of how it will change. A template isn’t always necessary. Some valuable materials, notably opal, are usually cut freeform for maximum weight retention. However, you’ll want to end up with calibrated sizes and shapes with most gem material, since these will fit into pre-made jewelry settings. Saving a little weight on most cabs but then having to spend time and money to make settings isn’t cost effective. Cabochon outline and saw guide lines When you’ve chosen your area, mark it for cutting. An aluminum pen is ideal for this. The mark won’t wash away like a pencil mark. Furthermore, many gem materials will absorb liquid ink, which leaves an unsightly and costly mess you’ll have to cut away. Once you outline your cab, take it to the saw and cut away as much excess material as possible. Until you get used to this process, drawing guide lines with the aluminum pen and ruler will prove useful. If you’re working with a large gem, you can move on to the grinding stage. Smaller stones should be dopped to save your fingers from unnecessary abuse. Shaping Now it’s time to start cutting. If you’re working with something hard, like a piece of agate, begin with your coarsest wheel. If you’re working with something soft, like opal or turquoise, or something small, begin with one of the smoother wheels. Of course, if the smoother wheel cuts too slowly, you can always go to a coarser wheel. However, it’s best to start gently with it. Getting Started Bring your machine up to speed and get your chosen wheel thoroughly wet before starting to cut. The water serves two important purposes. It acts as a lubricant, keeping the friction and heat down, and carries away the swarf (the cutting debris). This keeps the wheel from clogging. Most manufacturers recommend you use an additive for additional lubrication. Unless your machine is made entirely of stainless steel, you’ll need an additive with rust preventative properties as well. Use the lower quarter of the wheel when grinding. If you try to work above the centerline, the gem will probably be pulled out of your hands. “Pulled” is a tame word for what actually happens. The gem will be yanked violently from your hands and flung to the far reaches of your shop. If you can find the stone, it’ll likely be broken. Start by grinding the excess material down towards the outline you’ve drawn. Use a pair of calipers to measure your progress. Templates are great for shapes but aren’t accurate for dimensions. Leave yourself some room for the remaining steps. Depending on the size of your cab, you may want to leave a half-millimeter or so. This is something you’ll learn from experience. The amount varies with the hardness of the material and the size of the gem. Peeling the Apple Once you have the outline shaped, you’ll start the process called “peeling the apple.” Grind a bevel all the way around the gem at about 45º, bringing it 2/3rd to 3/4th of the way down to the bottom. Then, grind another bevel, all the way around the stone again, at about 60º. Leave some of the previous cut showing. Keep “peeling the apple,” cutting bevels at increasingly steeper angles, until they meet in the center. “Peeling the apple,” side view of 45° and 60° cuts This is the area that causes the most trouble for beginners. It may seem that just three cuts will completely cover the stone, except for maybe a tiny area right in the center. That’s not good enough. If you have even a tiny area that’s flat and not properly domed, the cab won’t take a proper polish. To make matters worse, the flat area will be right on the very top, where it shows the most! Be patient and learn to get the entire stone evenly domed. Look at the stone from both ends and both sides. The curvature should be even in every direction and all the way to the center. You should make this inspection at every step, but especially in the first, coarsest stage. Any irregularities are easier to correct now than later with the finer grits. Preparing for a Bezel Setting This next step may seem like you’re getting ahead of yourself, but it’s presented just so you know where you’re heading. As you’re shaping the gem, leave a small, vertical area on the sides before it begins to taper in. Also, sand a very small bevel on the lower edge of your girdle. This is done in the fine sanding stage. The bevel prevents the edge from chipping and also leaves a small area for solder. Sand a very small bevel on the lower edge of your girdle to prevent chipping and allow a little space for solder. Cabs are usually placed in a bezel setting. The bezel, a thin strip of metal, is soldered to the main piece. Hence, you need a little room for the solder. To hold the gem securely, the bezel needs to be bent inward, over the curvature of the stone. The vertical area on the side offers support without having to bend the bezel too far in. When finished, you want to see mostly the stone. You don’t want the bezel to come so far over the edges that it distracts from the gem. These steps are particularly important with brittle opal stones. If you leave a sharp edge on the girdle, the stone can chip or crack when tightening the bezel. The steeper the sides, the more support the gem receives. Of course, you can also overdo this. The illustration above shows the ideal proportions from the metalsmith’s point of view. Smoothing Once you’re satisfied with the shape of your gem, you’ll start sanding out the coarse scratches. If you’re using diamond, this will take a series of steps. Typically, you’d use a combination like 260, 600, and 1,200 grit. Inspect your gem after each step. Look for proper curvature, as you did before. Also, make sure you’ve removed all the coarse scratches from the previous step. This is very important. If you don’t get them all out before moving to the next step, you’ll either have to do it again or settle for a low-quality finish. The gem needs to be dry for you to see the progress. In a humid environment, this can be challenging. If possible, warm the room before starting. If you can’t warm the room, at least use warm water. Have plenty of towels available. Dry your hands before trying to dry the stone. If you are using silicon carbide, all you need is 600 grit. It wears fast and becomes the finer grit you need for a pre-polish. Unfortunately, these have limited uses. You may need to keep two 600 belts. Use one for shaping and another, well-used one for pre-polishing. I can’t overstate the importance of the quality of your pre-polish, the final fine sanding. This is the single most important element in getting a high polish. The surface should be ultra smooth, with no visible scratches at all. Any time you’re having trouble getting a high polish, go back to the pre-polish step. Soft materials like lapis and opal scratch readily with diamond. 1,200 diamond is a fine pre-polish for agate, but you might need something much finer, like 3,000 or 8,000, for softer gems. Cabochon cut from a piece of pink hydrogrossular garnet. Photo by R.H.C. Langendam. Licensed under CC By 3.0. Polishing Cabochons Polishing can be very confusing for a beginner. There are hundreds of methods. If you buy a new cabochon cutting machine, it’ll probably come with a polishing system. That’s a good place to start. Here are some tricks of the lapidary trade: Use aluminum oxide on suede, soft side out. This is the most versatile polishing method available. It’ll put a high polish on more materials than any other method. Quartz responds best to cerium oxide. This does well for opal, too, but be very careful about heat build up with opal. Stones get hot quickly during polishing, and heat can destroy opals. Jade, on the other hand, needs a lot of heat and friction to polish. Use chromium oxide on leather or felt. Diamond polish can be used on leather or specially made pads. However, it has never gained the popularity with cab cutters that it has with faceters. It’s more expensive than aluminum oxide and doesn’t offer any significant improvements, except on ruby and sapphire. These are the most common and most useful polishing methods. With them, you’ll be able to get a mirror polish on any material. That mirror polish is important. It takes a fair amount of work to procure a cabochon cutting machine, learn how to use it, find the rough, orient it, and finally cut a cab. Getting that mirror-high polish on a beautiful stone makes it all worthwhile. Top-quality Mexican fire opal cabochon in 14k gold ring with rose gold overlay. Photo and jewelry by Jessa and Mark Anderson. Licensed under CC By 2.0. Judging Your Cabochon Cutting When examining a cabochon, start by judging the polish. Look for any scratches or pitting that will reduce the amount of light reflected from the surface. Next, judge the shape. How even is the contour? A cabochon should have an even curvature to its surface. Look at the cab from both ends and both sides. The shape (the curvature) should be a mirror image from side to side. No area should be thicker than its opposite. There should be no bulging. Examine the shape further by holding the cab so light reflects off its surface. Move the gem so the light travels across the top. If the surface is properly cut, you’ll see the band of reflected light glide evenly over its surface. The band of light will begin to snake if there are any irregularities. Poor polishing will also affect how light moves across the gemstone. You’re most likely to see a problem at the top of the cabochon. Often, a small area will be somewhat flattened. From the side, this is hard to see. However, when light passes over the area, it’s obvious. The fact that light doesn’t flow smoothly over this area is why the cabochon cutting would be considered second rate. (If you look closely, that area probably doesn’t have a good polish, either). The oval is the basis for all cab cuts, even shapes like rectangles, teardrops, and hearts. Heart-shaped cabochons, left to right: hematite, rose quartz, tiger’s eye, and two sodalite stones. Photo by Mauro Cateb. Licensed under CC By 2.0.

Abrasive blasting is the general term applied to finishing processes that entail the high-pressure propulsion of a stream of abrasive material onto the surface of a workpiece. Abrasive blasting can serve many surface finishing purposes, such as removing contaminants or previous coatings, altering the shape and smoothing or roughening the surface. There are many types of abrasive blasting applications, each of which requires the use of different types of blasting materials, referred to as blasting “media.” Finishing Systems has assembled this abrasive blasting media guide to help you select the most appropriate material for your specific finishing processes. One note: the terms “sandblasting” and “abrasive blasting” are often used interchangeably. A conventional “dry” sandblasting process that uses traditional sand is not recommended for most applications. Blasting with sand generally requires twice the amount of material, making it cost-prohibitive for many companies. Glass Beads: Glass is not as aggressive a blasting media as other materials, such as steel shot or silicon carbide. However, it is an excellent choice for applications that require a softer, brighter finish. It is well suited for stainless steel applications. Glass beads can also be recycled multiple times. Aluminum Oxide: Aluminum oxide is characterized by its superior hardness and strength. It can be found in applications ranging from anti-slip surfaces, industrial applications as a blasting media, and as a raw material in refractories. It is designed for abrasive pressure blasting of almost any type of substrate: glass, granite, marble, and steel. Due to its ability to deeply etch it is used in the preparation of surfaces prior to painting or coatings. Plastics: Plastic abrasive is a dry thermoset cleaning media made from crushed urea, polyester or acrylic. Each varying and available in a range of hardness and particle size. Plastic is generally regarded as the best media for mold cleaning, blasting of plastic parts, or in applications where the removal of the substrate material is not permitted. Common industries include automotive, aviation, boating, electronics and industrial applications. Silicon Carbide: Silicon carbide is the hardest abrasive blasting material available, making it the best choice for your most challenging surface finishing applications. It is available in various colors and purities. Its primary use ranges from bonded abrasive tools, lapping, polishing, glass etching and general purpose heavy duty blast cutting applications. Steel Shot & Grit: Steel abrasive is a cost-effective alternative to other abrasives due to its toughness and high recyclability. It can be used on a variety of surfaces to effectively remove contaminants, texture a surface for proper adherence of a final coating, or in peening (hardening) applications. The correct size, hardness and shape play a significant role in the proper media selection. Starblast: Starblast™ is a mined loose blend of coarse and fine staurolite sands with extremely low levels of silica making it an ideal general purpose blasting abrasive. It is perfect for removing scale and corrosion from steel surfaces, while offering a low dust level for improved visibility. Walnut Shells: Walnut shell abrasive is a hard naturally occurring material made from crushed walnut shells. It is the harder of the soft abrasives, available in a variety of sizes for blast cleaning and polishing softer surfaces that could incur damage from harsher abrasives. Typical applications include polishing of soft metals, fiberglass, wood, plastic and stone. It can also be used in tumbling operations for polishing gems and jewelry. Corn Cobs: Corn cob abrasive is a granular abrasive manufactured from crushing the dense woody ring of a corn cob into various grit sizes. It is the softer of the naturally occurring abrasives making it ideal for cleaning, deburring, burnishing and de-flashing applications. Common industries include jewelry, cutlery, engine parts, fiberglass and the removal of graffiti or debris from wood, brick or stone.

Emery cloth differs to sandpaper in several ways: Emery cloth has the abrasive glued to a cloth rather than paper, which makes it far sturdier and less inclined to tear in use Emery cloth uses a form of corundum (or corundite) as the abrasive, rather than sand Emery is longer lasting than sand as a glued abrasive Emery particles are of a more consistent size than sand, especially where finer grades are concerned Emery should not be used on wooden surfaces as fine particles of iron and other metals can become embedded and cause staining or other damage to the wood Emery cloth is typically graded into "grit" sizes between 8 and 120, with the grit becoming coarser as the number increases. 80 grit paper is typically used for roughing and chamfering plastic pipe.

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