Rock Collecting and Rock Tumblers in Speciality Crafts & Hobbies(236)

You can find rocks suitable for tumbling in several places. Local riverbeds, beaches, and hiking trails often have smooth stones that work well. Rock and mineral shops also sell rough stones specifically for tumbling. Additionally, some rock tumbling kits include starter rocks to get you going. When collecting rocks outdoors, make sure to follow local regulations and obtain permission if needed. Choosing rocks that are hard and durable, like quartz or jasper, will generally give better results in your tumbler.

Good tumbling rocks are typically hard, durable, and not prone to crumbling. Rocks like quartz, agate, jasper, and petrified wood are popular choices because they polish well and hold up during tumbling. Avoid soft or porous rocks like chalk or limestone, as they can break down quickly. You can test hardness by scratching the rock with a steel nail; if it scratches easily, it might not be ideal. Also, rocks with cracks or fractures may break apart during tumbling.

The tumbling process usually takes several days and happens in stages. Rough grinding can take about 3 to 7 days, followed by finer grits for smoothing and polishing that may take an additional 4 to 7 days. Many rock tumblers come with timers and speed settings to help manage this. The total time can range from 7 to 14 days depending on the rock type and desired finish. It's important to check progress regularly and change grits as recommended for the best polish.

Cleaning rocks before tumbling helps remove dirt and debris that could interfere with the polishing process. Start by rinsing the rocks under running water to wash off loose dirt. For stubborn grime, use a soft brush or toothbrush with mild soap and water, then rinse thoroughly. Avoid harsh chemicals that might damage the rocks. Let the rocks dry completely before placing them in the tumbler. Clean rocks help ensure the grit works effectively and prevent contamination between tumbling stages.

Filling the tumbler barrel correctly is key to effective tumbling. Generally, fill the barrel about two-thirds to three-quarters full with rocks and grit. This allows enough space for the rocks to tumble and grind against each other without overcrowding. Overfilling can reduce the tumbler's efficiency and cause uneven polishing, while underfilling may not provide enough friction. Follow the instructions provided with your tumbler kit for specific recommendations based on barrel size.