When I was a child I really enjoyed rocks. Whenever we went to a mineral store or a national park I would buy a few shiny rocks for my collection. One of the things I always wanted was a rock tumbler to make my own rocks. When our second oldest son showed an interest in rocks, we decided to get him a tumbler so he could make his own.

We looked at a few choices, but finally went with the National Geographic Rock Tumbler. It had the best reviews, and it came with extras we would have had to buy separately. We have had this tumbler for a few years and have done several batches of rocks. I had considered doing a post before, but it seems like people are looking for things to do with their kids right now so it is a good time.

The rock tumbler is easy to use right out of the box. It comes with easy to understand instructions for the first time you use it. There are enough rough rocks and grit for one use. You will have to get more grit if you wish to use it again.

The grit is what smooths and polishes the rocks. There are four levels. The course grit will take off large parts of the rocks, reducing the sharp edges and taking off weaker sections. There are two medium levels that will further reduce the sharper edges of the rocks. The final level is the polish, it doesn’t reduce the rocks, but instead makes them smoother. Some types of rocks will be quite shiny after the polish.

As I said you will need more grit if you use this again. There are a number of options available on Amazon. The National Geographic refill is more expensive, so we went with another brand. So long as you buy a grit with the 4 levels then you shouldn’t have any issues.

One other thing you will need is extra belts. There is a rubber belt that goes from the drive motor to turn the barrel. The kit did come with one extra belt when we bought the rock tumbler. Since it is just a rubber belt, it will only last so long. We found that it is possible to buy extra belts on Amazon from third party vendors.

As far as rocks go I have seen them on Amazon, but we have never bought them that way. We have tumbled random rocks we found while hiking. We also tumbled gravel before, because one of the kids thought it looked nice. We just finished a batch of Petrified Wood that we bought at the Tucson Gem and Mineral Show this year.

Petrified wood after the second run, the first medium level
Petrified wood after the third run, the second medium level

I think these rocks turn out well. We ended up with quite a few shiny ones. Some of them still had some rough sections, but I think that is related to the hardness of petrified wood. Those rough patches seem to make the rocks more interesting so I am fine with them.

Mitzi felt that she needed to “help” me take pictures of the rocks. I couldn’t help but take a few pictures of her since she was cute. She moves a lot so it was hard to get any that were not totally blurry.


Be geeky with us!