rock tumblers, anyone had / use one

eldest (age 9) wants a rock tumbler, has had an interest in rocks and geology for quite a few years

anyone have one or used one? it looks like it will add up for all the various bits. are the national geographic sets okay?

plus can he just dig up any interesting looking rock and chuck it in or will he have to buy stones all the time?

All you’d get in most instances is turning any old  bits of rock slowly into pebbles.. Unless you have seems of jasper, agate etc locally to exploit, and then you’d get colourful pebbles, but they’d all be the same colour. So I guess the idea is you buy the stones

If the ‘interest’ in rocks and geology actually extends to going places – ie you taking them places – where interesting rocks can be collected- then instead of buying rocks you could plan your family holidays around interesting bits of geology

Christ don’t encourage him.

Have you ever met any rock lickers in the realworld?!

But on serious note… He will also need a hammer, the big picks are pretty unweildy but the smaller masons hammer is a pretty good compromise for smaller people whilst maintaining a chisel edge.

I used to mess with one many years ago.

As above, it worked as advertised for things like opal and rose quartz bought from lapidary suppliers but I didn’t have much luck with any UK ‘found’ rocks. No matter how pretty they looked in the field, they wouldn’t polish.

The machine needs to run continuously for days / weeks and they make quite a bit of noise in operation, so best kept in a garage or shed. They go through quite a bit of grit (the coarse stuff, especially) and the polishing powder can be expensive. If you have two barrels, one of them can be dedicated to polishing. Don’t empty the sludge down the drain…

I had a quick look at the Nat Geo kits and my first reaction was sticker-shock. I then found the kit that I had, and got an even bigger shock:

BRITISH Rock tumbler – 3lb dual evans stone tumbler / rock polisher starter kit

£168! I don’t think it was more than about £60.

Ultimately, there was only so much interest I could conjure from turning bought material into random shiny rocks (that you could buy ready polished if you had the urge to). It might have been different if I could have done something with collected material.

Don’t do it.

Expensive, irritatingly slow and noisy to achieve disappointment*.

*Sounds like the title of my Sex Tape 🙂

We had one at home as a kid to polish the quartz pebbles found on North Norfolk beaches- I spent hours combing Blakeney point for stones and found some really nice ones. As above, it takes days and is noisy- we had ours in the garage and you could hear it faintly in the house. The results were lovely but the polisher was probably used about ten times max and then left to be eventually thrown away about 20 years later.

Edit:

I have just remembered that I think my dad made his own with a spare motor he had at work, some pillow block bearings and steel rods. The container was bought from a lapidary supplier as was the grit

My son (8) has one. He loves it. It does take days/weeks and makes a load of noise but maintains his interest. It’s the national geographic one – hasn’t broken yet and seems to do the job.

We go for walks and end up with pockets full of rocks. We are off to Cornwall next week and will no doubt come back with a car full of serpentine.

It’s not that cheap (polish costs more than expected) but I’m happy to fund anything that we can do together outdoors.

thanks for the comments, he already knows its going to take along time to see results, it was the first thing i said! we already spend alot of time looking for fossils / rocks when we go to various places so hopefully the tumbler will add to the interest.

i cant really see the appeal of just buying stuff and sticking it in the machine, may as well just buy them polished (he already has a decent collection of bought stones)

I had one as a child and absolutely loved it.  Filled it with a mix of mystery cornish rocks and the odd bag of rough tumble mix a shop in St Ives used to sell and had some pretty good results.  I am still (for my sins) a practicing geologist so it didnt put me off.

Serpentine is lovely stuff but it might not tumble that well as its pretty soft. Boring H&S hat on as well, it can rarely be a bit asbestiform so maybe a quick dad inspection prior to it all coming home  (I found a few VERY questionable samples from various fieldtrips when picking up my old rock collection from the parents)

I’ve got a relatively cheap one off aliexpress, I’ve never used it for rocks though, I use it for derusting nuts and bolts. It’s pretty irritatingly noisy, especially in reversing mode which makes it pretty hard to “background” but I do like putting orrible things in and getting shiny things out, so I can see the appeal for rocks.

Not a recommendation for this seller but this is the one I have.

https://www.aliexpress.com/item/1005006291798130.html?spm=a2g0o.productlist.main.1.42f16a7fBbakNv&algo_pvid=c5bd8d06-d798-4eb7-bb2a-6aa6bff56aba&aem_p4p_detail=202408161224371252407597371040000857612&algo_exp_id=c5bd8d06-d798-4eb7-bb2a-6aa6bff56aba-0&pdp_npi=4%40dis%21GBP%2188.46%2159.27%21%21%21793.36%21531.55%21%40211b6d3517238362769748307e23e7%2112000036641828355%21sea%21UK%21726428969%21X&curPageLogUid=tn5M6ebzp41v&utparam-url=scene%3Asearch%7Cquery_from%3A&search_p4p_id=202408161224371252407597371040000857612_1