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 10:26am

Comments: 56 - Hits: 38885

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 PebblesatmyFeet on 10/18/2014 @ 10:20am

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 @ 10:16am

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 10/17/2014 @ 09:29pm

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 @ 09:11am

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 @ 02:52pm

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

By Guest on 09/12/2014 @ 09:01pm

Which dremel took is this

By PebblesatmyFeet on 09/05/2014 @ 08:28am

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 @ 10:16am

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!

By Guest on 06/25/2014 @ 10:01pm

thank you sooo much PebblesatmyFeet for sharing this info. I am going to buy the stand for my Dremel. Rimona

By PebblesatmyFeet on 05/27/2014 @ 11:32am

To the Guest who asked about sealing stones instead of tumbling them - the answer is yes, maybe, but there's more to it. Tumbling does more than make the surface shiny. It rounds and softens the stones, it reveals (sometimes unfortunately) cracks and flaws that might make you reject the stone for jewelry making, and it will give a shine or a beach stone effect depending on how far you take the tumbling process. See my post for more: http://www.artfire.com/ext/shop/blog_post/PebblesatmyFeet/8899/tumble-polishing_stones_for_my_handcrafted_jewelry

By Guest on 05/26/2014 @ 07:18pm

Is there a good varnish or sealer to use instead of tumbling?

By Guest on 04/26/2014 @ 07:59am

Thanks for sharing!

By PebblesatmyFeet on 04/08/2014 @ 02:55pm

Yes, if feldspar is tumbled with similar softer stones, it will take a polish. It doesn't take that deep wet-look polish that a piece of agate or petrified wood will, but I've been able to achieve a nice semi-gloss shine. I use plastic pellets in the later tumbling stages to take up volume lost.

By Guest on 04/08/2014 @ 03:40am

Do you really tumble feldspar to a polish? I had some that I put in my tumbler for only 4 days and it wore away quite a lot. Everyone tells me it won't polish because it's so soft.

By PebblesatmyFeet on 04/03/2014 @ 02:48pm

To the guest who asked about sea glass - glass is very similar to quartz in hardness, so I would expect it to drill like amethyst or agates. That means to me, it will burn up bits pretty quickly. Keep the piece under water and go slowly!

By Guest on 04/03/2014 @ 02:32pm

Thank you for sharing, have been wondering how I could better utilise my crystal pieces other than making bezels which are not my favourite pastime, and how to use my dremel for drilling holes in stones and glass.

By Guest on 03/29/2014 @ 06:37am

I wonder about sea glass pendant type, will it go well with the Dremel and with workstation?? I am a crafter and have excellent workshop room( used a LOT by my dear dad, now passed) but haven't cleared the room out and set up a real workshop yet... I am not sure to go ahead and buy a new drilling tool and try to drill sea glass and still spending a lot on new bits and so often... Question is how many holes in a bit can make ??? Let's say 1/8 thick sea glass and 1 mm hole???

By Guest on 03/22/2014 @ 11:16am

I'm a retired general contractor . I'm 59 years old. I have normaly worked with wood,steel, and bones as my art mediums. I recently started working with stones. I find it be very much fun .If some people are familiar with hand held grinding tools, like my 4 inch makita, You can buy diamond cutting wheels for the grinder and experiment with cutting and polishing stones. I recently cut and shaped a cool pendant and earrings for my wife. try it. thanks, Kip

By Guest on 03/10/2014 @ 10:23pm

Hi, Thanks for your talent. Amazing items. I am looking to make some items but do not even know where to begin. Could you give me some advise on getting started on making items from stone. I LOVE stone and really want to get something going for me with stones. Thanks in advance, Mike Novack :)

By PebblesatmyFeet on 03/07/2014 @ 06:17pm

Hi Jo, and thanks for your comment. There are two supplemental posts here as well - be sure to have your friend take a look. Cheers!

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