Collecting Stones for Rock Tumbling

Rock tumbling is a fun and educational hobby for all ages. The same is true of rock collecting. Both are popular activities enjoyed by people of all ages, backgrounds, and experience levels because they're accessible, fascinating and filled with surprises. When you're first starting out with rock tumbling, the idea can be a little intimidating. The number one question novice tumblers ask is how to choose the proper rocks for their tumbling adventures. The information below is designed to help choose stones for rock tumbling and introduce you to the world of rock collecting. Basic Guidelines

The type of stones you use for rock tumbling is entirely up to you; what is recommended is that you stick to stones of similar hardness when tumbling various rocks together. This will ensure they all take approximately the same amount of time to reach the proper smoothness, and that harder stones don't damage softer stones during the tumbling process.

When you're rock tumbling with various types of stones, try putting several together that are different sizes. This promotes thorough tumbling. If you're wondering how a certain rock will look after tumbling, try getting it wet - this is a good approximation of what it will look like after it is tumbled and polished.

What to Avoid

When rock tumbling, avoid using stones with pits or crevices on the surfaces, since these won't tumble to an entirely smooth finish. In addition, cracked rocks or those with large protruding ends or jagged edges will not result in a pleasing product. You can waste a lot of time and a lot of polish trying to smooth out crevices and holes in a poor rock; or you can start out right by only using the best rocks when you begin your tumbling project.

What Kind of Rocks Should I Use?

It's okay to put any kind of stone in the rock tumbler. Agate and Jasper are great for tumbling because they're easy to round and have a lustrous shine when polished. Any rock with a hardness of 5-7 on the Mohs hardness scale will generally take a nice polish in a rock tumbler.

Harder rocks usually result in a high-gloss finish. Softer rocks will get smooth and rounded, but they won't take a polish. If the rock looks earthy, it will generally still look earthy when you take it out of the tumbler. If it looks glassy before you put it in, it will generally take a good polish.

Where Do I Collect Rocks?

You can find rocks almost anywhere and learn how to identify them while adding them to your collection. Quarries, natural cliffs, hills, and steep slopes are great rock collecting sites. A trip to the water or walk through the woods is fun but not necessary. You can collect rocks right in your own backyard. Many novice rock collectors are pleasantly surprised to learn how many interesting types of rocks exist in their own neighborhood.

What Do I Need to Collect Rocks?

While not mandatory, a good classification guide or rock collecting encyclopedia can help you identify the rocks you find. A geologist's hammer comes in handy if you need to break off rock specimens or trim them to a more manageable size. Advanced collectors may want to consider a hand lens, or pocket magnifier, to identify mineral grains.

Other pieces of equipment are inexpensive and likely items you already have: a backpack, bags and paper to wrap and transport your rocks; a notebook for jotting down notes; a first-aid kit; protective eyewear; hard-toed shoes; and gloves.