Opal Cutting and Polishing
Processing Opal from Rough state to completion
This appeals to certain folks who like to learn new hobbies and know that in today’s economic climate it can be a way of either making a few extra dollars in the garage, or at least using their productions as items to give away. Opal Gems hold international appeal, obviously because of their amazing change of color and adaptability to different outfit preferences. Hence you can guarantee to produce a gift that will be much appreciated.
Gemstone cutting of course encompasses all varieties of precious items such as sapphires, rubies, emeralds, etc, but most of these items require a very high degree of time and skill that is not always so rewarding.Satisfaction from Opal Cutting There’s nothing more exciting than to take a rough piece of opal with remnants of the ground it came from attached, and with a few simple machines, turning it into a magnificent opal jewelry (jewellery) piece.
And keep in mind that if you do become an expert it won’t be long before you gather quite a few loose opals that you can select from to fit the personality of the person you are giving it to. You have to get used to terms such as ‘lapidary rough’ and ‘lapidary supplies’ as the term ‘lapidary’ has to do with the production of cut gemstones.
Opal Gem Jewelry creations is your goal and with a bit of effort you can find where to get pendant chains and accessories so that the piece you have made can be installed in a gift box with an appropriate card. As precious as these gems are, they don’t have to be really difficult to cut and polish. Australian opal rings and pendants along with other accessories are a real delight to produce and deal with. You can also offer your stones for sale online as well as in your local newspaper, particularly the classified ads. Rough opal is available on this site if you want to experiment.
Opal Cutting Procedure
If you see yourself becoming an expert cutter, continue reading this extensive article which will introduce you to the methods and machinery necessary to pursue your goal. If you can afford $35 after you have read this article you can order the cd: ‘the ordinary bloke’s guide to opal’ which will give you over 30 years of experience in the opal and opal jewelry or jewellery business. (‘jewellery’ is the English spelling and ‘jewelry’ the US spelling of this word) If you happen to have some rough of your own and you don’t want to learn how to cut it yourself, you can take advantage of our opal cutting and photography service described later in this article. Keep in mind that there is now an eBook available instead of the CD. Free to opalmine customers.
Making sure you get a good polish
The term ‘opal cutting’ might seem to indicate that it refers to someone who just cuts through a stone with some sort of saw but there is a lot more to cutting rough opals than just making an incision. We are talking about lapidary rough opal that needs to be processed to produce designer cabochons.
The fact is that the term is a bit misleading because it is used to describe a lapidary that is a cutter and or engraver of a stone. And it must be said that a gem cutter does much more than just cut stones.
The art usually starts when someone sets eyes on the stone itself. To anyone with an eye for beauty this initial contact with the stone leaves a memorable impression. Some just desire to own the stone set in a pendant or a ring. Others want to take it further and lean all about its history, it locations, its mining potential, hot is processed from the rough state to a finished opal gem.
Focusing on the cutting process itself, the idea is to take a piece of rough opal in your hand, often from a parcel of stones bathed in water. In most cases it’s necessary to use water on the stone because it gives a clearer picture of the stone you are examining. Unless you have very good dyes, a pair of jeweler’s magnifying glasses will help to identify faults and help you make a decision about where to make the first incision.
A quick word about the cutting procedure itself. In case you are not familiar with sintered diamond blades. These are metal blades that have an edge made up of a mixture of metal and diamond (as opposed to plated wheels, which as the description implies have diamond dust plated on the outside of the metal, not actually enclosed in the metal, and this tends to wear off sooner. So if you are thinking of becoming a serious cutter, get the best blades.
Diamond blades need water to be run over them to operate properly because the blade has to be kept cool while it does the job of slicing through hard material although it must be said that opal, in contrast to most other stones, is a pleasure to cut and does not wear your blades out as much as (for example) agate, crysoprase, chalcedony, etc. After some practice, the cutter will get the ‘feel’ of the blade and avoid putting too much pressure on it and jamming it. Just allow the blade to find its own way through the stone without forcing it because this could produce disastrous results, such as a broken gem, a broken blade, and maybe a cut finger.
Depending on the rough stones you have, opal cutting and polishing can either start with the diamond blade or with the grinding machine. Sometimes you have to use the grinder to clean up the stone a bit so that you can either expose the color more or see where there are any cracks and inclusions. Then you can slice the stone to suit. But sometimes it’s obvious what should be done and you can start with the blade. The two machines work in tandem, checking for color and deciding what the front and the back of the stone will be.
After the cutting procedure is complete, the stones potential is more exposed and you are ready to take it to the next stage which is the grinding wheel. Make sure you have good lights over your work, keeping in mind that you are working with water so it’s wise not to have electrical equipment too close to your work. Some nowadays are opting for 12v lighting systems to improve safety in this area.
Whether you are using the old style carborundum wheels or the new style diamond wheels, the same principle applies. To make sure there is plenty of water poring over your work to avoid overheating and to get the best grinding results. During the process you are cleaning up the stone more. Stopping regularly to examine for faults, cracks and inclusions. Your goal is to get as much color out of the stone as possible without leaving unnecessary inclusions that will take away from its beauty.
To achieve this goal, it’s a good idea to have in mind what you are going to do with the stone when it’s complete. For example, are you going to set it into a pendant or a ring? Is your main concern to get the most color out of the stone or do you want a particular shape such as an oval or a square stone? Keep in mind that if you make an oval, you are going to waste some material because all edges have to be ground away. On the other hand, if you leave it free form, it may be more difficult to set because the jewelry piece might have to be handmade instead of caste, which can be more expensive. More on jewelry setting can be found in the ‘opals for the ordinary bloke’ CD, which is now available online to select customers. Please leave your details here if you are interested.
Free forming opal by hand can be a delightful experience and brings out the creativity in you when you get away from the standard shapes. And of course if you venture into the art of jewellery or jewelry (depending how you spell it either the Australian or American way) making, the creativity just explodes. It won’t be long before you will be known as ‘The Opal Man’ in your community.
If you are going to become a professional opal cutter, you have to learn how to cut perfect ovals without drawing them. Of course you can use a template when you start off but after a while your eye will get used to perfect shapes and you won’t have to keep using the template after a while. To achieve this goal you can experiment and practice with lots of cheaper stones that you can cut out of the colorless potch or ironstone that will come with most parcels.
As soon as the stone has been fashioned by hand, now is the time to take it to the next level, which means putting in on a small piece of wood that is called a ‘Dop Stick.’ Before you do this you will have to cut yourself a bunch of these sticks out of dowels that you can buy from the hardware store. Some perhaps ¼” diameter. Others a little thicker, right up to the thickness of a broom stick for larger stones. So that you don’t have to have a dop stick holder with different thicknesses of holes which would be a pain, you just make a blunt point on the end of each stick so that they all fit the same hole in the Dopstick stand (bottom left)
Of course if you have a bunch of stones, it’s better to dop them all at once so that they can all dry together, giving you plenty of work to do the next day without having to wait for them to dry. You can use the old Metho and ceiling wax system if you want to have it ready in a few minutes but this is tedious and time wasting. This system is explained fully in our CD “the Ordinary Blokes Guide to Opal”
The machinery you use for the next steps that bring you to the final polish is pictured below. The grey, orange, and pink wheels to the left are the three last steps in bringing the opal to completion, but some still use the old fashioned cerium oxide as a final polish over and above diamonds.
Some opal cutters such as myself still prefer the old wet and dry sanding disc shown on the left, and the cerium oxide leather lap on the right. Even if you use the diamond machines for the first part of the process I still find that finishing off with these old reliable methods give a better final polish.
The most important sandpaper grits to use in my opinion are 320 and 600 before the final polish. 320 is so important to make sure all deep scratches are out and 600 just gives it that nice clean up before the cerium oxide. You have to experiment with different papers from different manufacturers. We always liked the old Nikon paper or Matador from Germany but these are no longer available as far as I know in Australia but may be where you live. We are currently using Norton paper here which seems OK but some papers are just no good for lapidary opal cutting for some reason. So just buy a few different types and experiment. It won’t be long before you get the ‘hang’ of it.
As far as obtaining rough opal from Coober Pedy and Lightning Ridge as well as opal jewellery, you can check out our site and you can buy loose natural opal, benefit by a world gem cutting service and if you don’t want to do it yourself, have your opal cut for low prices. And you will be pleased to know that we are currently planning to set up opal auctions. Because opal cutting is always associated with lapidary rough rock, you need to get diamond lapidary tools and machinery from Lapidary suppliers. Leave a message on the Chat Forum below and Peter will help you with this.
Lightning Ridge – History, mining, traveling are all terms we use to get to know about the opal industry and of course you could add Coober Pedy, Winton, Koroit, Yowah, Quilpie, Andamooka, White Cliffs and others to that list.
Leave a message on the blog below if you would like to get a copy of our new movie on the subject of opal cutting.
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