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How to make a round cabochon: 5 steps to cut a cabochon

Updated: Mar 11, 2022


There are several types of cuts within the art of gemstone cutting. One of the most common is the cabochon cut, which is characterized by being completely smooth.


Cabochons can be cut in different ways. Basically, this depends on the characteristics of the stone or the need that exists at the time of cutting.

For example, an opaque emerald doesn't need a specific shape based on its physical properties. Being a completely opaque stone, it can be square, irregular or pear!


However, other gemstones are cut as round cabochons in order to exhibit optical effects or phenomena such as cat's eye and asterism.


Round cabochon cutting also depends on the design of the jewel or piece of goldsmith. This cut was used quite a bit in ancient times and continues to this day!

Do you want to know which stones are cut in a round cabochon? Are you interested in knowing the key steps to make this well-known cut?


So, let's start talking about its advantages and discover the importance of one of the most classic gem cuts!


Advantages of the round cabochon


Cutting a gemstone in a round cabochon cut has its advantages!

  • It is one of the two cuts used in gemstones with asterism, such as the star sapphire.

  • It is frequently found in gems such as chrysoberyl and apatite, which have the cat's eye effect (chatoyancy).

  • In gemstones such as fire opal, it highlights the play-of-color property.

  • It is a timeless cut that is used in both classic and contemporary jewelry.

  • The organic and symmetrical design allows the round cab to be easily combined with other cuts in the same jewel. That's why it is common to find a central cabochon surrounded by smaller smooth or faceted stones.


Mexican Fire Opal round cabochon | Oscar Bautista Gemcutter
Mexican Fire Opal round cabochon

As you can see, cutting a stone in the shape of a round cabochon has significant benefits. And on gems with optical effects, it is a necessary cut.


But what are the other stones that can be cut in a round cabochon?


Could it be that this cut is only used on opaque gems or those with special characteristics?


Find out the answer below!





Gemstones in round cabochon


Basically, any stone can be cut in the round cabochon cut. It doesn't matter if it's completely opaque or translucent!


However, it is quite common to find this cut in the following gems:


  • Agate

  • Amethyst

  • Amazonite

  • Aventurine

  • Cat's eye chrysoberyl

  • Pink quartz

  • Rutile quartz

  • Emerald

  • Garnet

  • Jade

  • Jasper

  • Lapis lazuli

  • Malachite

  • Onyx

  • Opal

  • Moonstone

  • Ruby

  • Turquoise

  • Star sapphire

So if you have some of these rough stones and want to cut them, you already know that the round cabochon cut can be a great option.


If you work in jewelry or goldsmithing and you want to set round cabs in your designs, take the opportunity to mix two or more stones according to the harmony or contrast of their tones.

Also dare to look for other less common gems, such as the Larimar from the Dominican Republic. You will be surprised how many alternatives are on the market!

As you can imagine, working with round cabochons is simple. You will always find options in physical or online stores.


But what if you need a round cabochon stone and you only get it rough or in a different size?


How can you have custom cabochons to fit jewelry with certain designs and sizes?


If you have asked yourself these questions and decided that the best thing for you is to learn how to cut your own designs, you are in the right place.


Read on and learn the key steps you need to take to make a round cabochon cut!


5 key steps to cut a round cabochon


We cut the round cabochons on the machine we use for gemstone faceting. Yes, we only change the polishing discs!


The machine has a system known as the Jamb Peg, which is characterized by using a numbered arm.


This is one of the fastest and most efficient gem cutting methods out there, allowing you to cut more gemstones per unit of time, with fewer inputs and with a high level of precision.


It's the same machine that is used in Colombia to cut emeralds!

The steps that you are going to see below are focused on this gem cutting system.


But don't worry! Regardless of your tool, the process is very similar to transforming a rough stone into a round cab.


So let's start talking about cutting and making the preform!


1. Gemstone cutting and preforming


To get started, you should ask yourself the following questions:

  • What dimensions should the cabochon have?

  • How big must the rough stone be to get a cabochon with these dimensions?

  • Do I have a rough gem that is close to that size?


Selecting the stone for cutting the round cabochon | Oscar Bautista Gemcutter
Selecting the stone for cutting the round cabochon

If the rough gem is close to the cabochon size, you probably don't need to cut it.


But if it is a much larger stone, perhaps the ideal is to cut it into the pieces you require.


Cutting a stone before grinding it helps you make better use of the material: you can save smaller pieces for future projects and avoid using the diamond lap unnecessarily.

In case you need to cut the stone, follow these steps:

  1. Turn on your sawing machine.

  2. Activate dripping water.

  3. Start cutting the gem.

  4. Rotate the material until the cutting lines meet.


As soon as you have cut the stone to the desired size, you should begin grinding the base on the faceting machine.


To do this, turn on the machine and place the base of the stone on the diamond lap, moving it gently while the disc rotates.


Once the base is homogeneous, you can draw a circle on it. This way you will know how much to rough it up!


Start turning the gemstone until you get your round preform.

Roughing the round cabochon | Oscar Bautista Gem Cutter
Roughing the round cabochon

Now that the preform is done, let's move on to dopping and rounding the gemstone.


2. Dopping and rounding the gemstone


This phase has two objectives:

  • Give the stone a round shape.

  • Make the bevel.

And to make a good round shape, we're going to use the Jamb Peg!


The Jamb Peg is also known as numbered arm or simply arm.

First of all, you need to dop the stone to the dop stick. To do so, follow these steps:

  1. Heat the dopping wax and put it on the dop stick.

  2. Heat the gemstone a little.

  3. Heat the dopping wax that is on the dop stick and glue it to the stone.

In this step, using the centering tool helps you improve the position of the dop stick in relation to the stone.


Using the centering tool to cut the round cabochon | Oscar Bautista Gem Cutter
Using the centering tool to cut the round cabochon

Once the stone is attached to the dop stick and well centered, place the diamond lap and turn on the faceting machine. It's time to make the bezel!


To create the bezel, put the dop stick in a small number on the Jamb Peg.


Keep in mind that you must rotate the gemstone constantly until you get the round shape.


Rounded stone to cut into cabochon | Oscar Bautista Gem Cutter
Rounded stone to cut into cabochon

When the stone is completely round and you feel comfortable with the bevel, you can begin polishing the base.


3. Polishing the base


The polishing pad is king at this stage because it will give your stone its shine!


To polish the base you must do the following:

  1. Remove the diamond lap from the machine.

  2. Put on the polishing pad.

  3. Turn on the gem cutting machine.

  4. Put the stone on the polishing pad until it is shiny.

Remember that dripping water is essential in all gem cutting processes. Make sure the lap stays wet!


Polishing of the round cabochon base | Oscar Bautista Gem Cutter
Polishing of the round cabochon base

Once the gemstone has the desired shine, remove the dop stick from the dome and dop it to the base.


It's time to round the dome!


4. Rounding the dome


In this phase you are going to cut the stone until the dome is the shape and size you need.


The first thing you need to do to round the dome is to remove the polishing pad.


Then put in a diamond lap for grinding. Use laps with different granulations to obtain a better finish.


Rounding the dome of the round cabochon | Oscar Bautista Gem Cutter
Rounding the dome of the round cabochon

Begin by cutting the dome with the Jamb Peg. Choose the numbers depending on the angle and the shape you want to get.


Once you're done, go over the dome freehand. This will give the gem a better finish!


Round cabochon dome | Oscar Bautista Gem Cutter
Round cabochon dome

Now you just need to do the final step: polish the dome!


5. Sanding and polishing the dome


To polish the dome, use these two elements:

  • Water sandpaper.

  • Polishing pad.

Put the sandpaper on a firm surface and begin to move the dome of the stone following its curved shape. Take the opportunity to eliminate any lines or pores.


Sanding the round cabochon | Oscar Bautista Gem Cutter
Sanding the round cabochon

Once the dome is completely smooth you can move on to the polishing pad. Remember to always use water with a constant drip.


Polishing the round cabochon dome | Oscar Bautista Gem Cutter
Polishing the round cabochon dome

As soon as the dome is shiny, remove the dop stick from the base and you are done!



As you can see, cutting a round cabochon is a simple process. Basically you need to:

  1. Define the size of the stone.

  2. Put the dop stick in a central position to the gem.

  3. Make a good preform.

  4. Roughen the dome paying attention to the desired angles.

  5. Polish the gem with the help of sandpaper and the polishing pad to obtain a good finish.

Now would you like to see the whole process by the hand of the gemstone cutter?


Do you want to visualize the step by step, as if you were in front of our gemcutting machine?


Then, check out our virtual course on Making Round Cabochons below.


Learn online how to cut a round cabochon


You know that experience is acquired with practice!


For this reason, we have created a virtual course for you to learn how to cut round cabochons.


With this course you have 3 main benefits:

  1. You see every detail of the process as if you were in front of our gem cutting machine.

  2. Your course is activated for two months and you can do it at your own pace.

  3. You can access from any device with an internet connection: computer, tablet, mobile.

Making Round Cabochons Virtual Course | Oscar Bautista Gem Cutter
Making Round Cabochons Virtual Course

Course cost: 25,00 €


Now, let's see how widely used round cabochons are in jewelry.


Use of round cabochons in jewelry


Round cabochons began to be used since ancient times.


It is known that early cultures used onyx, turquoise, jade, and lapis lazuli cabochons not only in jewelry, but also in crowns and pectorals.


The round cabochon has been one of the favorite cuts of goldsmiths and designers for its versatility and timelessness: it never goes out of style!


If you go to a jewelry fair, you'll surely find pieces with round cabochons. It is one of the most sought after cuts by jewelry buyers!

Therefore, using round cabochons in jewelry is always a good option.


You can find round cabochons in:

  • Earrings

  • Pendants

  • Rings

  • Bracelets

  • Brooches

  • Cufflinks

It is common to find jewelry with a single cabochon, which is usually a good size stone. This happens with many rings.


There are also jewels with several cabochons of different colors, set side by side.


You can usually see rings or bracelets that have a sapphire cabochon, an emerald cabochon, and a ruby cabochon. Of course, you choose the gemstones!

Finally, jewelry is made with a central cabochon surrounded by other smaller gems. An example can be some rings or pendants.


Honduran opal round cabochon pendant | Oscar Bautista Gem Cutter
Honduran opal round cabochon pendant

But if you are looking for options other than gemstones, don't worry.


There are other materials such as glass that are perfect for making round cabochons.


Alternatives to gemstones: round glass cabochons


The round cabochon cut can be made in gemstones, but also in some synthetic materials and glass.


Using glass to make round cabochons has important advantages:

  • It can be easily cut due to its hardness.

  • Depending on the jewel, the glass resists the pressure of the setting.

  • It is available in an infinite number of colors.

Another favorable point is that you can find glass easily since it's a material that is produced worldwide. You can buy glass at home and decoration stores.


Using recycled glass is a more sustainable practice and may help you cut costs.

Finally, you can see glass cabochons in various jewelry. For example, this silver ring is set with a recycled pink glass cabochon.


Silver ring with round recycled glass cabochon | Oscar Bautista Gem Cutter
Silver ring with round recycled glass cabochon

As you can see, with round cabochons the possibilities are almost endless!

Recommendations


If you have a gem with optical effects like asterism or cat's eye, you can cut it into a round cabochon. This cut will highlight its properties!


Pay attention to every step of the cabochon cutting process. Keep in mind that the preform and roughing will determine the quality of the round cut.


The round cabochon is one of the most widely used gemstone cuts worldwide. Use it alone, in combination with other cabochons, or as a centerpiece.


Dare to innovate! If you want to use materials other than gemstones, use glass. It has the right hardness and is easy to get.


Experience comes from practice! The more cabochons you cut, the better the result will be.


If you want to go deeper and see every detail of the process as if you were in front of our gem cutting machine, take advantage of our Making Round Cabochons Virtual Course.


FAQ


1. What are the advantages of cutting a round cabochon stone?

The round cabochon is one of the world's favorite cuts and is used on opaque and translucent gems. It's one of the two ideal cuts for gemstones with asterism, cat's eye effect and play of color.

2. What are the steps to cut a round cabochon?

3. In which jewels are round cabochon gemstones set?

4. Is it possible to cut other materials in round cabochon?

5. Are there online courses to learn how to cut round cabochons?


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