How to Cut Agates

Co-authored by wikiHow Staff

Last Updated: February 12, 2020 References

Agate is a popular type of stone with gemstone workers because of its unique colors and patterns. The average agate is less than 3 in (7.6 cm) in diameter, but they can get up to 15 in (38 cm) wide or more. Agates have alternating bands of colors including brown, white, red, gray, pink, black, and yellow. Consider cutting the stone into slices to use for jewelry or simply cut it in half to make decorative rocks you could set on a shelf. Once you’ve cut the agate into smaller pieces, you can grind and polish them using a rock tumbler or sandpaper to smooth the agates out and enhance their colors.

Method 1

Method 1 of 2:

Slicing Agate with a Bandsaw or Table saw

1
Fit a bandsaw or table saw with a diamond-tipped blade. Ensure that the power saw is turned off and unplugged before you put a new blade on it. Remove any blade that is currently fitted in the power saw and replace it with a diamond-tipped saw blade.^{[1]
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- This method works well to cut large agates that you can easily hold on both sides in order to feed it into the bandsaw or table saw.
- A bandsaw utilizes a long skinny saw blade on a band that rotates around and through a work table, whereas a table saw has a round spinning saw blade mounted in the middle of a work table. Both can be used to cut agates equally well using the same process, so use whichever one you have available.
- You can buy a diamond-tipped saw blade for either type of saw at a home improvement center, hardware store, or online.
Tip: Use a saw blade that is thicker than 0.006 in (0.015 cm) for the safest option. Diamond-tip blades that are at least this thick can’t easily cut into your fingers.
2
Put on safety glasses or goggles and a dust mask. Wear safety glasses or goggles to protect your eyes from flying agate particles. Cover your mouth and nose with a dust mask to avoid breathing in any agate dust.^{[2]
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- You can get a good pair of safety glasses or goggles for under $10 USD online or at a home improvement center or hardware store. You can get a pack of multiple disposable dust masks starting at under $10 USD as well.
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3
Turn on the power saw. Plug the power cord from the bandsaw or table saw into an electrical outlet. Press the power button to turn the saw on and start the blade spinning.^{[3]
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4
Feed the agate straight into the saw blade, holding it flat against the table. Hold the agate firmly between both hands, leaving at least 3 in (7.6 cm) of space between your fingertips and where you want to make the cut. Press the agate firmly against the tabletop of the power saw, then carefully slide it straight into the blade of the saw to start making the cut.^{[4]
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- If the agate is too small to leave at least 3 in (7.6 cm) of space between your fingertips and the saw blade, you can place the agate in a pair of locking pliers and hold the pliers to guide it while you make the cut.
- Never feed an agate into the saw blade at an angle or you might bend and break the blade.
- You can cut a whole agate in half by cutting straight through the middle or through the fattest part so the 2 halves have equally-sized faces. You could also cut your agate into multiple slices of about 0.5 cm (0.20 in) or thicker.
5
Look straight at the saw blade while you cut. Position yourself so your eyes are lined up directly with the saw blade. Don’t take your eyes off the blade until you’re done cutting.^{[5]
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- This will allow you to make a straight cut as well as keep an eye on the saw blade to make sure it doesn’t bend.
6
Push the agate carefully into the blade until you cut all the way through. Keep pushing the agate into the blade while holding it firmly against the table to feed it through the blade. Push it all the way through until you cut the agate into 2 pieces.^{[6]
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- You can repeat this process to cut the agate into more pieces if you want. Remember to use locking pliers to guide the agate through the blade whenever the pieces become too small to safely hold between your hands.
7
Turn off and unplug the power saw when you are finished cutting. Set aside the agate you just cut. Push the power-off button to shut down the power saw and unplug the power cord from the electrical outlet.^{[7]
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Method 2

Method 2 of 2:

Using a Dremel Tool

1
Attach a Dremel diamond blade to a Dremel tool. Change the bit on a rotary dremel tool to a diamond wheel bit. These types of diamond wheels are made for cutting through many types of hard materials, including different types of stones.^{[8]
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- This method works well for cutting agates that are too small to safely hold in your hands to guide them through a power saw.
- You can purchase a Dremel diamond blade at a home improvement center, hardware store, or online.
- A Dremel tool is a handheld rotary tool that you can attach a wide variety of bits to. It is a good choice for cutting agate when you don’t have a large power saw available or when the agates you want to cut are too small to comfortably cut using a table-mounted power saw.
- Keep in mind that Dremel diamond blades only come in sizes up to about 3 in (7.6 cm). For stones bigger in diameter you will have to cut them on a table-mounted power saw.
- You can buy a diamond-tipped saw blade for either type of saw at a home improvement center, hardware store, or online.
2
Place an agate into a clamp mounted on a workbench to hold it in place. Open up a table clamp just enough that you can fit the agate in it. Tighten the clamp’s handle until the agate is held firmly in between the jaws of the clamp.^{[9]
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- Make sure the part of the agate that you want to cut is exposed when you clamp it.
3
Wear a dust mask, protective eyewear, and work gloves. Put on safety glasses or goggles to protect your eyes from agate dust or flying chips. Cover your mouth and nose with a dust mask to avoid inhaling agate particles. Wear work gloves to protect your hands.^{[10]
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Plug in and turn on the Dremel tool. Connect the Dremel rotary tool’s power cord to a power outlet. Switch the speed on the Dremel tool to the moderate setting, then press the power button on the handle to turn it on.^{[11]
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- The moderate speed setting will ensure you don’t damage the blade, the motor, or the agate.
5
Cut into the agate slowly using the Dremel tool. Hold the Dremel tool securely in both hands. Press the spinning diamond blade against the agate firmly where you want to begin the cut.^{[12]
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- If you aren’t confident that you can eyeball the cut, you can mark the agate with a permanent marker beforehand to help guide you.
- You could cut your agate in half by either cutting right through the middle or by cutting through the fattest part. You can also cut an agate into multiple slices of at least 0.5 cm (0.20 in) or thicker if you want.
6
Move the Dremel blade slowly through the agate until you finish cutting. Keep pushing the blade straight into the agate until you cut all the way through. Go slowly to avoid chipping the stone or heating up the blade too fast.^{[13]
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- If you can’t cut all the way through the stone from 1 side, just cut as far as you can, then pull out and turn off the Dremel tool. Rotate the rock 90-180 degrees in the clamp before you continue to cut all the way through.
Warning: If you see the Dremel blade starting to turn red, back it out of the cut and turn it off. Let it cool down before you continue.
7
Turn off and unplug the Dremel tool after you finish cutting. Press the power button to turn off the Dremel tool and wait for the blade to stop spinning before you set it down. Set down the Dremel tool on a flat surface and unplug the power cord from the electrical outlet.^{[14]
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