THE PHILADELPHIA GROUP-Amazing Science Kits: Super Growing Crystals. Watch these crystals grow from tiny gems to magnificent crystals just by placing them in water. Use them over and over again! This kit contains three super growing crystal packets in assorted colors, one test tube, and an instruction 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. Imported.