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The Thames & Kosmos Rock Tumbler is a kids' science kit that turns rough stones into polished gems. It ships with real rock samples — amethyst, aventurine, rose quartz and more — plus four polishing grits and jewelry settings to make finished pieces. A leak-proof, noise-reducing barrel and built-in timer make it easier to live with than bare-bones hobby tumblers, and the manual and poster add geology lessons on erosion, weathering and the rock cycle. It suits families and young collectors; adult hobbyists who want fast, large-batch results may find a single small barrel limiting.
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The Thames & Kosmos Rock Tumbler turns rough stones into polished rocks. It also introduces topics like erosion, weathering and the geological rock cycle. It is designed for ages 8 and up.
The kit includes authentic rock samples, such as amethyst, aventurine and rose quartz, along with four polishing grits. Jewelry settings and fasteners are included, so polished specimens can be made into accessories. After polishing the included rocks, you can also tumble rocks, glass, wood and other materials you collect.
The machine has a long-lasting motor, a leak-proof, noise-reducing barrel and a built-in timer. The timer has several settings and can run for up to seven days. A manual and poster explain how to use it and cover how different types of rocks are formed.
