How I Drill Holes in Tumbled Stones for my Handcrafted Jewelry

How I Drill Holes in Tumbled Stones for my Handcrafted Jewelry


Published On: 09-16-2012 05:26pm

Comments: 68 - Hits: 66556

Category: About my Artisan Jewelry and Jewelry-making in General

I like using tumbled stones in my handcrafted jewelry. As I wrote in an earlier post, I like their natural free form shapes and the degrees of polish possible when I process stones in the rock tumbler. For many of my artisan jewelry designs like simple pendants or my Pebbles’ earrings, the stones need to be drilled.

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My husband and I have a full woodworking shop.  However, I knew our woodworking drill press would not do for tumbled stones. You see, you don’t actually drill through a stone like wood rather you grind the stone away. It's more like drilling concrete or tile. You need higher speeds and (obviously) smaller drill chuck for stones. When the bug first bit me to drill some of the tumbled stones I brought back from my childhood home, I looked to what I had at hand: a Dremel tool. The Dremel offered appropriate maximum speed (and range if I could vary it) and a variety of available useful accessories but was not enough just on its own.

My Dremel tool stone drilling station.

My Dremel tool is a basic single-speed one. With the addition of a tool stand (around $45 from Amazon at the time) and foot control (from the household sewing machine) I’ve put together a useful stone drilling station. As a bonus, the Dremel stand is also useful to hold the tool at right angles for grinding and polishing. I use it often this way to polish silver and copper wire components for my jewelry.

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The Dremel tool on the left for use as a hand tool. On the right is the Dremel stand or workstation.

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The Dremel tool mounted in the workstation. The big blue handle moves the Dremel up and down like a drill press.

Benefits of using a foot control.

The foot control allows me to have the Dremel plugged in and “on” but not spinning until I apply pressure with my foot. It also gives me speed control; light foot pressure slowly starts the Dremel and more foot pressure increases the speed of the tool until it maxes out. I can hold the stone with one hand and operate the drill plunger to bring the bit to the work with the other hand while my foot activates the tool.

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The sewing machine electronic foot control that I use in my stone drilling station. Note that the Dremel is plugged into the outlet on the control that says "motor".

Other accessories needed:

The keys to drilling through stone are using an appropriate abrasive, keeping the bit cool and free of the clogging stone dust that is generated, and having plenty of patience with your technique. I use a plastic tray that I fill with enough water to just cover my stone. I use a thick piece of leather (two pieces actually) underneath the stone to prevent drilling through my reservoir. You could use a piece of wood or plastic. You just need something to stand off the bottom of the tray that is soft so that the drill bit won’t be harmed as it breaks through the stone. I keep a water bottle handy as I work to top off the bath or to wash the drill bit from time to time. The purpose of the water bath is to keep the drill cooler and to wash the drill and the hole of the stone slurry.

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I use a plastic tray (from a frozen food entree) to hold water enough to cover the stone. Also shown is the leather pad and a plastic bottle cap that I use to hold the stones off the bottom of the tray. The leather works really well to uniformly support the stones.

A bit about (drill) bits.

The abrasive of choice for drilling stones is diamond. I have used diamond burr bits and diamond core bits. A burr bit is a solid bit with the abrasive on the face and partway up the sides. A core bit is hollow at the cutting end with abrasive on the face and inner and outer walls. Cores are generally “better” by which I mean they start a hole better and last a little longer. But be prepared: either type of bit wears out quickly with harder stones like agate or petrified wood. I get about two holes per bit in ¼-inch thick harder stones, whereas with softer stones like amazonite I might drill 5-10 holes with a bit. Diamond bits for drilling stones are available at many jewelry and lapidary supply outlets on line or in your neighborhood. I’ve purchased drills from Amazon, Mama’s Minerals, and Rio Grande.

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An assortment of diamond drills. A set of burrs is shown at top while a bunch of cores are shown at bottom.

Technique is everything.

What I’ve found works best is a pulsing technique. I hold my stone under water on the leather pad. I bring the bit down to the work and touch the stone. If it is cutting well, I see a plume of stone slurry begin to wash off and I hear a nice “dentist tool” sound. I touch the stone allowing the bit to grind for about one second, pull the bit up and then back down for about a second and so on like this. I feel that this prevents overheating; it washes the hole, and keeps me from putting too much pressure on the bit. If the stone slurry stops or the bit starts to “whine” it is time to change the bit. (Worn out bits can be used as grinding tools – using the abrasive on the side walls of the bit – for a time thus extending their useful life around the studio.)

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Here, I'm holding the stone under water on the leather pad. The drill bit is shown above the work. By repeatedly (and gently) bringing the drill down to the work a hole is slowly ground through the stone.

A danger with some stones such as feldspar (amazonite is a type of feldspar) is “chip out” or breaking flakes off the stone as the drill emerges on the back side of the hole. Although I can’t prevent this from happening all the time, I’ve found a few things that help.

1. Drilling stones before they’ve been through the final polish or even the pre-polish step in the tumbling process.

2. Embedding the stone in putty (plumbers putty is messy, but you can also use that stuff for mounting posters on the wall) on the backside to support any irregularities.

3. Stopping at intervals before completing the hole to see if you can see through the stone well enough to start the hole again from the back side. This has the most success. I will often mark the drill with a sharpie at the level where I think the drill will be just about through the stone. when I reach the mark, I'll stop drilling, dry off the stone, hold it up to the light to see if I can spot the hole from the backside, and use the sharpie to mark the center of the light spot on the stone. I return the stone to the drilling station and drill from the back side. As long as I’ve carefully marked the center, the holes usually line up well.

Drilling tumbled stones is a slow process. I find it meditative most of the time. If I find that I’m getting frustrated, well, then it is time to stop. Hopefully, by that time, I’ve accumulated enough drilled stones to satisfy my jewelry making efforts for many weeks.

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Edited to add new information: July 2014

I have written two additional blog posts on this subject:

http://www.artfire.com/ext/shop/blog_post/PebblesatmyFeet/10454/how_i_drill_holes_in_tumbled_stones_supplemental_information

http://www.artfire.com/ext/shop/blog_post/PebblesatmyFeet/14036/how_i_drill_holes_in_tumbles_stones_for_my_handcrafted_jewelry_-_summary_of_earliers_and_comments

Reader's Comments

By Guest on 05/04/2015 @ 08:25pm

Thank you so much Pebblesatmyfeet for taking the time and consideration to pass on all this wonderful information. I am about to purchase my first Dremel tool and start to drill holes in some beach stones that I have collected. My favourite past time is to collect stones from beaches and i've been dreaming of glorifying their beauty so-to-speak, by polishing them up and making jewellery with them. I'm really excited about the whole process and I'm determined to make some lovely jewellery (spelt the English way :)

By PebblesatmyFeet on 05/04/2015 @ 03:38pm

you can certainly make a blind hole (one that does not go through the stone) with a dremel and diamond bit. I think I would be inclined to soften the edge of the cylindrical hole that a drill would make by using a burr type bit afterward (also diamond)

By Guest on 04/29/2015 @ 03:16pm

Hi---Thanks for this great post!! Can you please tell me if this is the tool you would advise if I just want to make little holes on the surface of the rock to fill in with beads? Thanks

By Guest on 03/25/2015 @ 10:34am

I find that Harbor Freight is g r eat fir buying bits, filing tools and diamond bit cutters. Because I go through them so quickly, this store offers a cheap price and many of my other jewelry making tools at over 1/2 the price less than Lowes. Home Depot, Amazon and other "specialized stores'" that are outrageously priced.

By Guest on 02/18/2015 @ 03:35am

Where can I buy the cheapest diamond bits? I have a ton of jasper and agate pendants (60 or so) that need holes (two each!) and don't want to go broke on bits. Each pendant is about 5mm thick on average. thoughts? I'm willing to spend a little more to buy bulk for the future. Just looking to cut down on the per item cost.

By PebblesatmyFeet on 02/11/2015 @ 01:54am

Just to be clear - I do NOT drill at high speed. In fact I had to add the foot pedal so that I could slow down my single speed dremel tool. You are exactly right that slow is better.

By Guest on 02/10/2015 @ 06:21pm

Thank you so much for the information. One question though, why do you drill at high speed? I always thought drilling at slower speeds on hard objects works faster and the bits lasted longer. I have been drilling glass blocks for my wife to decorate for gifts, and have found that the slower speed was much faster and the bits lasted much longer. I would drill a smaller hole then enlarger it, and they didn't heat up.

By PebblesatmyFeet on 01/19/2015 @ 01:03am

There are no ridiculous questions or concerns when it comes to power tools. In my set up, since I have the Drexel in the tool stand, it is very secure. I am not holding it, so it is not likely to fall into the water. I clamp the stand to my workbench for added security. If you are holding th tool on your hand I suggest getting comfortable with the tools operation. Drill some wood or other dry stuff, then introduce the water and your diamond bits.

By Guest on 01/18/2015 @ 01:11am

This may sound ridiculous to you, but I am asking this with great sincerity. Are you not afraid of causing yourself bodily harm if the Dremel accidentally slips into the water? I have toyed with the idea of drilling my turquois with my Dremel, but I'm reluctant because water is needed to cool the stone. Comments? Suggestions? Thank you.

By Guest on 01/16/2015 @ 03:37am

Great article, I'm actually working on creating a ring out of a turquoise rough cut and am going to drill through it as the first step and then ream it out. Do you have any tips recommendations when working with turquoise stones?

By PebblesatmyFeet on 12/06/2014 @ 01:51pm

Hello, Suzi, and welcome to the conversation. for a 2mm hole, I think you could drill it once with a 2mm bit. I usually drill with 1.5mm. However, for a 3 or 4mm hole I do feel it would be best to drill with 1.5 or 2 first. at least that is what I would do. Hope that helps. Have fun with it!

By Guest on 12/05/2014 @ 09:19pm

Hi, If I want to drill a 2mm hole into quartz am I better to do it smaller first and then gradually move up to the thicker hole? Or would you just go right through w the desired thickness right away? Thanks Suzi

By PebblesatmyFeet on 10/18/2014 @ 05:20pm

The feldspar that I pick up around my home in Colorado is microcline feldspar - the pinkish stuff is very common, but amazonite is related. It tumbles pretty well, but I'd recommend tumbling it in a batch of feldspar only (not mixed with harder stones). Also, as you approach a finished polish, you'll need some plastic pellets in the tumbler to cushion the batch. Sometimes it comes out great and other times it continues to cleave and crack. I've got jars full that didn't make the jewelry cut so to speak. I use a Lortone tumbler for my rocks, but any rotary style would be similar.

By PebblesatmyFeet on 10/18/2014 @ 05:16pm

There is nothing particularly special about my Dremel tool, except that I already had it. It is a very basic one - corded, not cordless - and a single speed. I had two sewing machines that used a foot control that had separate wall outlet plugs and then receptacles that said "motor" and "light". you plug the sewing machine or dremel into the receptacle that says "motor". One sexing machine was from a Sailrite, and one was an older Montgomery Ward machine. Again, I used this particular control because I had it I'm not suggesting that you have to use one from a sewing machine if yours doesn't work that way. Here's a listing for a foot pedal speed control that would work. http://www.amazon.com/Nippon-Labs-STK-975PS-Flexible-Grinder/dp/B000VV4SDS/ref=sr_1_3?ie=UTF8&qid=1413652527&sr=8-3&keywords=dremel+foot+control

By Guest on 10/18/2014 @ 04:29am

What type of feldspar do you use? I have some great stones that I don't want shiny for jewelry but just to bring out some of the colors and details...would this work and do you have a favorite tumbler?

By Guest on 10/03/2014 @ 04:11pm

Hi, I have a large variety of tumbled stones specifically sized for manufacturing stone jewelry, I may want to sell some unique stones, I have many, if there are fellow stoners looking for some amazing stones, please feel free to contact me. Email markanthonywingrove@ymail.com

By Guest on 09/17/2014 @ 09:52pm

Where did you get the sewing machine pedal with the outlet on the end to plug the dremel into?

By Guest on 09/13/2014 @ 04:01am

Which dremel took is this

By PebblesatmyFeet on 09/05/2014 @ 03:28pm

To the Guest who inquired about drilling Herkimer diamonds - since these are quartz crystals ("hard" minerals) I would hesitate to drill them. with the double terminations (points) to the Herkimer diamond, it would be hard to find a good spot to drill that wouldn't compromise the stone's uniqueness. Have you considered wire wrapping? or prong setting one to wear?

By Guest on 09/04/2014 @ 05:16pm

Thank you all for the comments. I have learned something from each of you! Have any of you drilled holes in Herkimer diamonds? I collected quite a few, living in NY. They would make great jewelry. I guess I just need to give it a whirl!

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