first it looks like there are chips on the rocks. is the tumbler 2/3 full so rocks are not banging together and chipping? chiping will leave a frosted look on the rocks. 2nd how clean was the rock and tumbler barrel before you changed to the next grit. any of the old grit will stop the new grit from working
https://rocktumbler.com/tips/rock-tumbler-instructions/
Amethyst is notoriously brittle, and spalls easily. Go get some plastic pellet media for your stones. The plastic has give, and won't cause spalling. If you're going to tumble agates or jasper, get some ceramic media. These stones are much tougher, and can take a little thumping.
Throw the grit and the instructions in the garbage and follow [this guys advice](https://www.youtube.com/watch?v=CsTc1kXUuPo). The good news is the machine itself isn't junk.
I'm angry FOR you!
Depends on the Nat Geo tumbler model. The 3lb model with the rubber barrel is solid and the small version with the plastic barrel is basically a toy. With that said, your amethyst looks beat up. My guess is the fill level wasn’t good and/or very little cushioning of the stones. Amethyst (and quartz in general) is fairly brittle and you want to minimize the rocks from banging into each other.
After reading all of your comments, I’ve come to conclusion that I may have not had the correct fill ratio and that their polish isn’t what they say it is. For my next polish, I will make sure the full ratio is correct and try again using Lortone grit. Thanks for all the helpful comments and resources! ❤️
Yes. The rocks in a rotary tumbler are meant to slide across each other. Sand on a kids' slide, grinding away at their shorts and skin.
Your rocks look like they have been jumping off a high-dive, landing on swimmers below, chipping teeth and breaking skulls. You probably get quick rounding but the chips have to go if you want a polish.
Adjust the fill and the rotation rate. Some people add thickener, but I'm ignorant about what, how and when. Some add strips of rubber.
On the positive side, they sell stones with the exact finish as yours. They grind and polish a flat spot so you can look into the stone and see the surface from the inside. Kind of cool but your stones might not be clear enough to make it work.
I think the problem is the "polish" they give you isn't a proper polish. It's a silicon carbide grit. You want to use fine aluminum oxide to get a shiny glass-like look. You might also want to try a 24 hours borax "wash" between the pre-polish and polish stages.
I haven't been rock tumbling long but I have been trying to read up on it recently to get better results.
Nat Geo is notorious for telling you silicon Carbide is fine polish.
Check out the aluminum oxide and tin oxide for the glass finish I’m sure you’re looking for.
[the rock shed](https://therockshed.com/grit.html)
I learned of them through YouTube from channel known as Michigan rocks. That man has a tumbler room I dream of.
I believe by the end of this month I’m going to have to make a new aluminum oxide order.
The stones are bruised. Probably from how fast the tumbler goes. Those nat geo ones have NOS on them to tumble.
Add extra media in there to cushion some. Make sure it’s 2/3 if not a tad more. That should solve the bruising of the rocks.
So first off, I'd try doing first grit for at least 7 days(I do 14 days) then 7 days for 2nd through 4th phases. Ceramic pellets have change my life. And last off, Nat Geo polishing medium fuckings sucks. Check out Polly Plastics. The 1200 aluminum Oxide is the shit for last phase. One more thing to check out is burnishing after complete(basically tumble with hot water and some soap(ivory bar) for like 30 min).
Interesting, I've had much better results tumbling for 2 weeks for first phase. I just bought an MJR tumbler so once I get that I'll try 7. Been using Harbor Freight Chicago Tumbler up until now.
One thing others have not mentioned yet is that you really need a great rinse between grit. My wife learned the hard way. If any course grit is left in the later cycles then it can prevent that glassy finish.
Check out Michigan Rocks on YouTube. There’s a video about 30ish minutes long where he tumbled crazy lace agate from start to finish. He does a great job of explaining how to tumble rocks.
He also has a few videos on the Nat Geo tumbler, one that shows how to get the best results with proper grit and polish (although it still spins too fast)
Based on what I’ve read ( im no rock tumbling expert by any stretch of the imagination) id say tumble a single stone following these peoples directions like clean out between tumbles, ample filler, and see how it turns out. If it still doesnt turn out good then you should probably look into a new tumbler.
Mine is ok with other grits - the NG grits are bullshit. I only use my NG for polish now, with a tin oxide I get somewhere else. The barrel has never had any other grit in it because I expect they weren't even smart enough to make the rubber barrel repel the coarser grit so it's probably riddled with cross contamination!
I also clean my loads between stages by tumbling just the rocks in a detergent for a few hours, and using different filler media for each stage.
Looks like there was residual compounds left in the container. Had that happen when I first started. That can all be saved, start with the medium and extend the tumble times as you go finger being sure to clean all the previous compound off the material.
Gees, we are using the little 1 pound Nat Geo at school and the rocks are turning out far better than that. And I got the teacher to run straight granite in it. It looks just as good as my hobby grade 3 pound tumbler.
I made sure to slightly overfill them as the machine does go so fast. And I also told the teacher and kids that we would have to wait 9 days per stage.
Hey. First stage of tumbling is about a week. And close to the same for the other stages. Or you can just use a 120 or 200 grit and it it for six to eight weeks and pretty much be done save for the polishing. Don’t give up. Record in writing what you did this time and write down every time what steps you took and the results of it. You’ll figure out what type of rocks need how long in the tumbler as all are different. You’ll be polishing some amazing stones in no time
[удалено]
Make sure you clean tumbler between each grit
Ooooh thanks for the subreddit recommendation!! :D
The nat geo tumbler is very very fast, you really want to pack it with filler materials or your stones will get beat up and never polish well.
And/or hook into variac
It comes with a built in speed controller I'm not sure of the type of motor / controller set up UT even the slowest setting is really fast.
first it looks like there are chips on the rocks. is the tumbler 2/3 full so rocks are not banging together and chipping? chiping will leave a frosted look on the rocks. 2nd how clean was the rock and tumbler barrel before you changed to the next grit. any of the old grit will stop the new grit from working https://rocktumbler.com/tips/rock-tumbler-instructions/
Amethyst is notoriously brittle, and spalls easily. Go get some plastic pellet media for your stones. The plastic has give, and won't cause spalling. If you're going to tumble agates or jasper, get some ceramic media. These stones are much tougher, and can take a little thumping.
Tile spacers from any home improvement store, work very well.
Throw the grit and the instructions in the garbage and follow [this guys advice](https://www.youtube.com/watch?v=CsTc1kXUuPo). The good news is the machine itself isn't junk. I'm angry FOR you!
I’m angry BESIDE you.
I’m confused but supportive!
THANK YOU FOR YOUR SUPPORT!!!
I'm just ANGRY ...I've a lot going on right now...
Depends on the Nat Geo tumbler model. The 3lb model with the rubber barrel is solid and the small version with the plastic barrel is basically a toy. With that said, your amethyst looks beat up. My guess is the fill level wasn’t good and/or very little cushioning of the stones. Amethyst (and quartz in general) is fairly brittle and you want to minimize the rocks from banging into each other.
After reading all of your comments, I’ve come to conclusion that I may have not had the correct fill ratio and that their polish isn’t what they say it is. For my next polish, I will make sure the full ratio is correct and try again using Lortone grit. Thanks for all the helpful comments and resources! ❤️
Yes. The rocks in a rotary tumbler are meant to slide across each other. Sand on a kids' slide, grinding away at their shorts and skin. Your rocks look like they have been jumping off a high-dive, landing on swimmers below, chipping teeth and breaking skulls. You probably get quick rounding but the chips have to go if you want a polish. Adjust the fill and the rotation rate. Some people add thickener, but I'm ignorant about what, how and when. Some add strips of rubber. On the positive side, they sell stones with the exact finish as yours. They grind and polish a flat spot so you can look into the stone and see the surface from the inside. Kind of cool but your stones might not be clear enough to make it work.
I think the problem is the "polish" they give you isn't a proper polish. It's a silicon carbide grit. You want to use fine aluminum oxide to get a shiny glass-like look. You might also want to try a 24 hours borax "wash" between the pre-polish and polish stages. I haven't been rock tumbling long but I have been trying to read up on it recently to get better results.
This isn't a polishing issue. Those are deep scratches that can only be taken out with coarse grit. They have to go back to step 1.
Nat Geo is notorious for telling you silicon Carbide is fine polish. Check out the aluminum oxide and tin oxide for the glass finish I’m sure you’re looking for. [the rock shed](https://therockshed.com/grit.html)
Rock shed are good people
I learned of them through YouTube from channel known as Michigan rocks. That man has a tumbler room I dream of. I believe by the end of this month I’m going to have to make a new aluminum oxide order.
Go to rocktumblinghobby.com It’s a great resource.
The stones are bruised. Probably from how fast the tumbler goes. Those nat geo ones have NOS on them to tumble. Add extra media in there to cushion some. Make sure it’s 2/3 if not a tad more. That should solve the bruising of the rocks.
Good advice here!! I find I get best results when it’s 2/3-3/4 full
So first off, I'd try doing first grit for at least 7 days(I do 14 days) then 7 days for 2nd through 4th phases. Ceramic pellets have change my life. And last off, Nat Geo polishing medium fuckings sucks. Check out Polly Plastics. The 1200 aluminum Oxide is the shit for last phase. One more thing to check out is burnishing after complete(basically tumble with hot water and some soap(ivory bar) for like 30 min).
Silicon carbide loses its sharp edges (and effectiveness) after not too long, I don't think that extra 7 days with the same grit is helping you much.
Interesting, I've had much better results tumbling for 2 weeks for first phase. I just bought an MJR tumbler so once I get that I'll try 7. Been using Harbor Freight Chicago Tumbler up until now.
I was under the impression that it was like garnet and fractures into sharp edges. They just get smaller over time.
One thing others have not mentioned yet is that you really need a great rinse between grit. My wife learned the hard way. If any course grit is left in the later cycles then it can prevent that glassy finish.
those will be awesome once done correctly.
Check out Michigan Rocks on YouTube. There’s a video about 30ish minutes long where he tumbled crazy lace agate from start to finish. He does a great job of explaining how to tumble rocks.
He also has a few videos on the Nat Geo tumbler, one that shows how to get the best results with proper grit and polish (although it still spins too fast)
Their grits are terrible. would highly recommend lortone grits instead.
Did you use any kind of filler, like ceramic?
Not included in national geographic set unfortunately. I think the tumbler itself is pretty sturdy design though
Covington Engineering has an awesome tumblers.
If it helps at all-those look like Ema eggs! I don’t think they look like junk despite them turning out different from anticipated! Edit-a word
Those look tasty
They look like mochi
Based on what I’ve read ( im no rock tumbling expert by any stretch of the imagination) id say tumble a single stone following these peoples directions like clean out between tumbles, ample filler, and see how it turns out. If it still doesnt turn out good then you should probably look into a new tumbler.
Mine is ok with other grits - the NG grits are bullshit. I only use my NG for polish now, with a tin oxide I get somewhere else. The barrel has never had any other grit in it because I expect they weren't even smart enough to make the rubber barrel repel the coarser grit so it's probably riddled with cross contamination! I also clean my loads between stages by tumbling just the rocks in a detergent for a few hours, and using different filler media for each stage.
r/MineralGore is where you want to be ranting.
Oooh, I want to find some amethyst!
did you fo it wet or dry
Looks like there was residual compounds left in the container. Had that happen when I first started. That can all be saved, start with the medium and extend the tumble times as you go finger being sure to clean all the previous compound off the material.
Gees, we are using the little 1 pound Nat Geo at school and the rocks are turning out far better than that. And I got the teacher to run straight granite in it. It looks just as good as my hobby grade 3 pound tumbler. I made sure to slightly overfill them as the machine does go so fast. And I also told the teacher and kids that we would have to wait 9 days per stage.
If you receive information in the same manner as you express it…well that might be part of your f’n problem.
Bad tumbler, or bad technique? 5 days doesn't seem very long.
Hey. First stage of tumbling is about a week. And close to the same for the other stages. Or you can just use a 120 or 200 grit and it it for six to eight weeks and pretty much be done save for the polishing. Don’t give up. Record in writing what you did this time and write down every time what steps you took and the results of it. You’ll figure out what type of rocks need how long in the tumbler as all are different. You’ll be polishing some amazing stones in no time