Our latest Dig! Discover and Display kit is not just for excavating crystals and rocks, it’s for growing crystals, too! Each kit comes with two packets of mono-ammonium phosphate. Some packets of salt are dyed with food coloring to mimic crystals found in nature; however, each crystal structure is the same, forming tetragonal crystals. The dye actually washing off the crystals, so if you are not careful when removing the crystals, you might get dye on your hands or clothing, or it might mostly wash away if you run the crystals under water. It’s also imperative that you follow the direction precisely or your crystals may not grow. Though we warmed our water to the correct temperature, it’s possible some of our crystals didn’t grow as spectacularly as the clear ones because by the time we worked on those crystals the water had cooled down and didn’t adequately dissolve the crystal granules as thoroughly as the first batch. We also used glass jars and plastic beakers to grow our crystals rather than clear empty two-liter bottles as recommended in the directions. Our choices made it harder to see the crystals growing and harder to get the crystals out of the containers. In the end, the clear crystals seemed to grow the best, but the yellow ones were the thickest. The blue ones made a poor showing and the pink ones were pretty nice. Overall, we all enjoyed the whole process.