Good for a science-minded kid, but the noise and wait time are real commitments

The National Geographic Rock Tumbler is good for a science-minded kid, but the noise and the weeks-long wait time are real commitments that parents need to be ready for. My kid loved checking each day’s progress, but the constant low rumble meant we banished it to the laundry room. The finished rocks look great and my daughter was genuinely proud of them, but I’d only recommend this if you have a space where the noise won’t drive you crazy and a kid patient enough to wait for the payoff.