Rock Tumbler Instructions: Turning Rough Rocks into Beautiful Tumbled Stones
33 comments
·October 25, 2025pavel_lishin
zafka
You can pick up Silicon Carbide grit pretty cheap online ( impure moissanite ). I have several tumblers, but have yet to finish the process of making polished gems- but it is still on my bucket list :). I have made lots of "sea glass: though. I have taken quite a bit to the local beach ( about 40 miles north of Palm Beach Fl. ) I toss it into the surf, figuring it will make some beachcombers happy. My logic is that once it has been in the ocean a few days, it will actually be sea glass. I would not make that claim for any of the glass that comes straight out of the tumbler though. Next time you visit a craft show and see folks with "Sea glass" Jewelry, note if they have separate displays for "real" sea glass, and man made.
debo_
I add ceramic fillers to make sure the barrel is at least 3/4 full. It makes very little noise that way; I can't hear it when standing outside the door of the room I'm running it in.
I like the glass idea, that sounds fun.
dylan604
> ceramic fillers
Thanks for this tip. I'm planning on buying a friend a tumbler for xmas, and if this works as advertised, I feel this would be a must have as part of the gift.
Edit: of course, TFA mentions this as well for those willing to click the link <facepalm>
Mistletoe
My girlfriend loves sea glass and has a rock tumbler. I think we will try this, thanks!
jackbeck
I have strongly negative connotations with rock tumblers. When I was about 8 I saw one in a store and thought it would turn regular rocks into precious stones. One of the biggest disappointments of my childhood.
JKCalhoun
I hope you didn't buy Sea Monkeys next.
EvanAnderson
Lots of comments are talking about how loud rock tumbling is. I have an interest and space in my basement but I'm reticent to pull the trigger without knowing if it's going to be intolerably loud upstairs. Does anybody know how many dB the process actually generated?
Edit: Finally got to a PC to do some search-engine investigation and found this: https://rocktumbler.com/tips/how-much-noise-does-a-tumbler-m...
thangalin
Rock tumbler enclosure, soundproofing box.
EvanAnderson
I worry about heat dissipation, but maybe that's considered.
When I printed my "underground newspaper" on a dot matrix printer, back in high school, I thought I'd get away with so much printing without my dad knowing by putting a cardboard box over the printer to deaden the sound. It worked until it didn't. Luckily the printer had a thermistor on the printhead and just stopped versus continuing to brainlessly grind until seizing-up.
jimnotgym
I have favorited this thread. It has the best comments I have read in 10 years of hn.
I want to go and build a tumbler now. I'm imagining it is another good use for an old sewing machine (I hoard a few for projects)
juris
I’m making one out of a treadmill that I snagged over Covid (and subsequently never used)! Idea is to make a jig to hold the tumbler in place. Maybe make it removable so I can still choose to not use the treadmill.
YZF
I had a rock hounding phase in my life ... It was something fun to do with the family and we have a lot of interesting rocks in BC.
I built my own rock tumbler using some wood, hardware store bits, and an old geared DC motor... I also used commercial rock tumblers. Those worked better ;)
It takes a really long time to tumble rocks, you have to go through the grits like a week or two at a time, and they sort of come out without a lot of character. Hand polishing them (with power grinders and polishers) is a lot more satisfying and you can make them into your own. That does require more equipment though.
debo_
My first tumbler was built from a lawnmower my dad discarded when I was around 11 years old. I buried it in the forest and topped up the gas whenever I had time. It really did not work at all.
noman-land
Loved the twist ending.
DonHopkins
Do not fall into the trap of anthropomorphizing Larry Ellison!
kyrofa
Loved this as a kid. But as a parent, even putting it in the garage is just too much noise for my household, haha!
JKCalhoun
I think I like this post because, simpler things, simpler times.
nsxwolf
We had one last year and followed the directions exactly. The stones came out very smooth but cloudy and dull. Not sure what went wrong.
teiferer
That's cool and all but ... what's the point? What do you do with these rocks afterwords?
photonthug
Most people do this so that they can eat the rocks afterward. They are shiny and very nutritious, and it strengthens the teeth. It's normal for some teeth to break off during this phase, but a) you already have colorful rocks to replace the teeth with, and b) old broken teeth can now be placed inside the tumbler for smoothing. 9/10 geologists agree that unsmoothed teeth that aren't made of rock are the number one cause of oral hygiene problems
lossyalgo
+1 can confirm. Also the best rock candy is made with actual rocks.
jdlshore
People like the way they look and feel, and I imagine they get some satisfaction out of having turned a rough rock into something beautiful. They put them in their house where they can admire them, and others can admire them. Many are probably given away as gifts. Some might be used to create larger works of art, such as earrings or other jewelry.
j4coh
As best I can tell you can’t even properly monetise this or get VC funding. Seems like a waste of effort.
debo_
I have several children in my life who are going through a shiny objects phase. I ask them to give me rocks that they like, and then I tumble those rocks for them. They really seem to like it.
steve_adams_86
My son and I get a kick out of it. For a while he was selling them on the street outside our town home, and that was absurdly lucrative for him. He has made around $200 so far. I'm pretty sure it's because he's cute. In any case, it's just a fun thing to do and experiment with, learn, and explore.
I've also thrown a bunch into an aquarium as 'river stones', because it's illegal to take them from rivers here and buying them is way too expensive. Those are just bland, small pieces of dark granite to simulate the environment the aquarium is modeled after.
andai
Is shiny!
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RebeccaTheDev
I mean, it's a hobby? It doesn't necessarily have to have a point other than to enrich your existence.
I have a rock tumbler that I got as a present. It's neat, but this page is right - it takes a long time, and you end up using a lot of grit as well, and it must be done in order. Oh, and did I mention that it's noisy? Definitely not a hobby for ... me.
But! One thing I have found interesting is that you can make your own "sea glass", by breaking wine or beer bottles, and tumbling the big-ish chunks. The thicker the glass, the better, of course. I'm experimenting with just using some sand as the grit material; the glass doesn't come out shiny and smooth, but it definitely wears down the sharp edges.
(And I run the tumbler thing in our detached garage.)