Tumbling is a technique used for smoothing and polishing a rough surface on small particles. Professional rock polishers help jewelers polish stones by imitating the abrasion of rocks in nature. The natural process happens over hundreds of years, and tumblers speed it up by acting like liquid sandpaper. Softer rocks like limestone and sandstone polish easier while granite and quartz require weeks of tumbling.
The independent variables in this experiment are the types of rocks. The dependent variable is the effect of the tumbler on the types of rocks. The constants are the jars, the water and the process.
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