Recommended Grade: All Ages

Rock tumbling has been a favorite in our family for a while now and we highly recommend this activity for your kids. Our kids are mesmerized by the smooth, polished stones and pay close attention to the different lines and patterns in each gem. Cue the geologist! This is the perfect time to teach about mineral properties.

We have prepared free downloadable worksheets to make rock tumbling both fun and educational. Because rock tumbling is a long process (see patience below) we are going to break this out into a series of posts/lesson plans. Check out our getting started with rock tumbling worksheets now!

Materials:

• A tumbling machine (we used National Geographic Starter Kit)
• Rough gemstones
• Polishing grit
• A strainer
• GeoKidz Tumbling Log (linked here)
• Something to write with

Tumbling machine

How do you know which rock tumbler is right for you? It mostly depends on how much material you plan to tumble. If you want to polish large batches of rock at a time, some common high-capacity tumblers can handle as much as 15 pounds. However, smaller batches might be a better option if this is a hobby you plan to start with your kids. National Geographic has some great rock tumblers for kids. Here are our favorites:

National Geographic Starter Kit – We use the National Geographic Starter Rock Tumbler with our kids and are quite impressed with both the durability and quietness of this tumbler. It is a smaller tumbler so it can only handle about one pound of gemstones at a time. This one is available for under $40.

National Geographic Hobby Rock Tumbler – Another great option from National Geographic. The National Geographic Hobby Rock Tumbler can hold two pounds of gemstones at a time and comes with a programmable timer. This one is available for around $70.

Gemstones

You can purchase rock tumbling mixes online or even polish rough stones you find. GeoKidz provides one-pound tumble mixes that include beautiful gemstones such as rose quartz, jasper, sodalite, blue aventurine and more. Keep in mind, minerals with sufficient hardness such as varieties of quartz are desirable because softer minerals will be pulverized.

Grit

There are usually about 4 different grit sizes or steps you go through to achieve the polished look you are seeking. Each grit is about 7 to 10 days of tumbling.

Patience

It takes time to achieve a smooth polish. But the best part is, this is one of the greatest lessons learned tumbling rocks!

Remember oceans and rivers take thousands or even millions of years to polish stones. It’ll probably take you about one month!

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Looking to add to your Mineral & Rock Collection?

Check out GeoKidz GeoKidz Dig Kit and GeoKidz Mining Adventure Mother Lode Sluice Mix. Both are great options to not only add to your collection but also a great way to learn about each Rock and Mineral.

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Link to mentioned products.