• Caelen Burand

Guide: How To Cut Rocks

Updated: Jul 17, 2019

At Cholla Lapidary, we enjoy spreading our philosophy and knowledge on cabochons and rockhounding compiled over a lifelong pursuit of revealing Earth's treasures!

This beautifal Creede amethyst has just been cut using the methods described in this article.

WARNING: Cholla Lapidary is not responsile for any actions takeen while cutting rocks. Always follow manufacturer instructions when operating machinery.

Ever curious what the inside of that rock looks like? Even the rocks with the dullest, unappealing exteriors often have beautiful minerals to display within! Take thundereggs for example, usually within basalt or rhyolite their exterior's are never appealing yet their insides can have nearly every form of agate! The problem is accessing these beautiful interiors; luckily at Cholla Lapidary we will help you learn to cut rocks to display their interior!

Warning: Simply cutting a rock will NOT give it a polish, instead it will simply create a flat surface that must be wet or polished to be recognizable as anything significant. Cholla Lapidary does offer the opportunity to transform your rough rocks, or unpolished slabs into beautiful cabochons, exemplifying their natural beauty by shaping and polishing the stones. For more on this service please click here.

Choosing Equipment:

Choosing the correct equipment for your cutting needs is quintessential for cutting rocks and subsequent lapidary endeavors.

Option 1.) Tile saw (Recommended)

For most rockhounds and lapidarists, a large rock saw designed for slabbing (cutting thinner cross sections of a rock) is far too expensive (often costing thousands). Instead a tile saw fitted with a diamond blade is the perfect solution. Here at Cholla Lapidary we use a 7 inch tile saw fitted with a diamond blade (continue reading for how to choose a blade). While many are deterred by its small blade size (traditionally only able to cut rocks up to 3.5 inches) the ability to angle the blade upwards means we can often cut stones up to 6" x 6". Do not be deterred by the prospect of a smaller tile saw, most rocks are surprisingly able to be cut by these saws. In comparison to a true rock saw these come at a much cheaper cost (hundreds vs. thousands) as well. The only discernible difference we have found between true rock saw and our tile saw is their price and the size of material cut. Other than this, these two options perform equally! Because of the price, the tile saw is the optimal for rockhounds and everyday cutting. This option has been working for Cholla Lapidary for several years as our tile saw has spent hundreds of hours cutting stone and we have never encountered an issue.

Option 2.) Dremel (Recommended for trimming slabs)

Our Second recommendation for cutting is using a dremel with a diamond blade attachment. This is great for cutting very small stones or trimming slabs for lapidary work, but the small size means that the blade often only penetrates about half an inch into the stone. Most geodes or rough rocks will simply be too large to cut using this method. The small depth does work excellently for trimming rough slabs in preparation for lapidary work. If using this method, be cautious of dust and chips of stone, they are common. ALWAYS wear eye protection and a dust mask.

Option 3.) Rock Saw (Recommended with reservations)

This option is superb for cutting very large stones like large Brazilian agates or massive geodes, but the very large size and accompanying expense means it is often unpractical and unnecessary for most rock cutting. We recommend this for cutting slabs of stone measuring over 10" x 10", anything under this size can likely be cut using a tile saw and the resulting cuts will be parallel. We find these saws too expensive for the little use it would receive for our lapidary work, and find this is the case for many. If interested in cutting a very large stone many local rock shops and some jewelry stores will have a rock saw capable of cutting stones feet in size and will cut a stone for you.

Because of our extensive practice using the tile saw option the article will continue under the assumption of using a tile saw to cut rocks.

Choosing a Blade:

For cutting rocks ALWAYS use a diamond rimmed wet blade advertised for cutting tile or brick. Furthermore, we have not found a discernible difference in quality among brand or price.

Option 1: "Continuous" blades (Recommended for precise/fragile cutting)

These diamond blades are characterized by a simple diamond rim without any cutouts or ridges. They work perfectly for all rock cutting, providing the smoothest cut of any blade design. Because of the smooth cut we recommend their use for cutting slabs or more fragile rocks. Other blade designs often increase the likelihood of a rock shattering upon being cut. The downside of this option is the blades wear-out slightly faster than ridged blades and take far longer to cut harder stones, like agates. At Cholla Lapidary we cut most of our slabs (the thin sections of rocks then trimmed for cabochons) using a continuous diamond rimmed wet blade.

Option 2: Ridged "Turbo" Blades (Recommended for cutting sturdy rocks, non-slab cutting, and trimming)

These blades are the most durable and cut rocks the fastest on the market. Their drawback is they vibrate the stones more and offer a less precise cut. We recommend using these blades to cut geodes without hollow centers or to cut rocks that do not have many fractures. For slabbing purposes we recommend these blades for agates and hard stones without fractures. At Cholla Lapidary we use these blades on a variety of our slabs that are far less fragile, like larger agates or geodes without hollow centers.

Option C: "Segmented" Blades (Not Recommended)

We do not recommend using segmented blades for cutting rocks. This is because we have found in our trials these blades often become dull rapidly and shatter stones. If using these blades take precaution of small chips of stone becoming airborne and the hazards surrounding a stone shattering while being cut.

Cutting Stones:

After gathering the proper equipment it is time to cut!

1.) Safety: ALWAYS wear proper ear, eye, and safety gear for cutting stones. At Cholla Lapidary we use a breathing mask, eye and ear protection when cutting. Even when using a wet saw there is inevitably harmful dust emitted and rock chips flying at harmful velocities when cutting. Before cutting we always check our saw's setup is proper by running it for a brief period to ensure the saw has been properly constructed.

2.) Finding a proper position to cut: Place the stone on a solid "face" (an edge that will not wiggle while being cut) and align the rock with the blade as you would like it cut. If there is not a face to set the stone on to prevent wiggling using wooden blocks or duck tape significantly helps. Ensuring that the stone does not move when it is being cut prevents the rock from shattering.

3.) Let the Saw do the work: When pushing your rock through the running saw do not force the rock through. Adding pressure by forcing the rock through increase the chance the rock shatters and dulls the blade. Instead, gently push the tray the rock is on and let the saw do the work. Even when blades become dull and it is tempting to force the rock through, it is not worth shattering your rock to save seconds on a cut.

4.) Have Extra Water Available: There are numerous occasions we believed we had enough water in our bucket to cut a rock and were very wrong. To resolve this, we always have an emergency bucket of water available to quickly pour into our main reservoir bucket for the pump without shutting off the saw. NEVER run the saw dry, this is dangerous because of the dust emitted and can damage the saw, blade, and your rock.

Next Step: Polishing

After cutting you will quickly notice your rocks do not display a polished shine like many would like. To learn to polish stones to reveal their beauty check back with our blog as we will explain that soon! This process is far from simple and often is far more time consuming and technical than cutting the stones. If you would like to remove that difficulty from your life please read below!

Want Cut/Polished Stones Without the Money/Work? We have a Solution!

Of course using a tile saw and then polishing rocks to get a perfect shine is not for everyone. Luckily we have custom cutting and cabochon creation at Cholla Lapidary. This provides you with the opportunity to see the interior of that stone or geode you love without the hassle! Furthermore we can use our decade of practice to transform your stone into a beautiful cabochon! We have a decade of experience using our lapidary prowess to make the perfect cabochons that extenuate every rock's natural beauty! To see more click here.

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