Amazing Science Kits: Marble Laboratory. Place these tiny colored pebbles in water and in just while you will have your own squishy, slimy, bouncy marbles! This kit contains over 100 multi-colored marble pebbles, 1 test tube, and an instruction/ex periment sheet. Recommended for ages 8 and up. WARNING: CHOKING HAZARD-Small Parts. Not for children under 3 years. This set contains chemicals that may be harmful if misused. Adult supervision required.